⚽ Returning Terry sent off as Chelsea progress in cup
It was a great victory for Antonio Conte’s men who recorded their first win after losing to Tottenham Hotspur in the Premier League on Jan 4 2017.
The Blues rolled out nine changes for the third-round tie and practically trailed when Asmir Begovic saved Lee Angol's short proximity header.
Chelsea had 20 shots by half time, with Pedro's curled finish and a drilled Michy Batshuayi effort giving them a cushion, before Willian drove in from 18 yards after the break.
Chelsea captain John Terry saw red for bringing Angol down as the last man and was then sent off. Tom Nicholls prodded in from six yards for a buoyed Posh, only for Pedro to restore a three-goal advantage from the edge of the box.
This win gives Chelsea a boost ahead of the Premier League and the FA Cup title games, question is, will they pick up the energy in their upcoming games?
"With this in mind, I feel now is the time to seek a new challenge.
"I'm delighted to be joining Tianjin TEDA FC at a time that the Chinese Super League is really taking off, and I look forward to helping Tianjin TEDA FC continue to grow.
"To play in the Premier League is every professional player's ambition.
"But to play for Chelsea, to become part of the Chelsea family to work with some of the best managers and players in the world, has truly been an honour.
Mikel is the second Chelsea player to move to the Chinese Super League in recent weeks following Oscar's transfer to Shanghai SIPG. BBC contributed to this report.
⚽ Alli stars as Spurs end Chelsea's 13-match winning streak
Dele Alli's ninth and 10th Premier League goals of the season proved enough to end Chelsea's winning run.
Tottenham ended Chelsea's attempt to make Premier League history with a 14th successive victory as the title pacesetters were well beaten at White Hart Lane.
Spurs moved up to third place as headers from Dele Alli either side of half-time made the difference to leave Chelsea five points ahead of Liverpool in second place.
Alli rose to meet Christian Eriksen's cross in first-half stoppage time and the same pair combined to put the game out of Chelsea's reach in the 54th minute.
Eden Hazard had Chelsea's two best chances in each half but Spurs closed out the victory in comfort to put north London rivals Arsenal out of the top four and leave themselves seven points off the top after their fifth successive league win.
Spurs have won five straight games in the Premier League
Tottenham's season was at a tipping point after a disappointing Champions League exit at the group stage and the poor performance in defeat at Manchester United in early December - but they have responded magnificently.
Mauricio Pochettino's side are gathering impressive momentum, illustrated by the manner in which they overcame a Chelsea side that was starting to carry an air of impregnability.
The 4-1 wins at Southampton and Watford served as a warning that Spurs were approaching the sort of form that carried them close to the title last season and this performance confirmed their growing confidence and stature.
Spurs have recaptured their intensity and energy and when this is bolted on to the quality provided here by the likes of Alli and Eriksen, it makes them a formidable prospect.
Manchester City had already found Spurs too hot to handle at White Hart Lane this season - and Chelsea suffered a similar fate.
Alli delivers the goods
Alli's first (left) and second (right) goals were remarkably similar efforts
Alli endured a quiet start to the season, perhaps in the aftermath of England's debacle at Euro 2016 - but the 20-year-old is firing on cylinders now.
Alli's headed double here made it seven goals his last four games, the third time in succession he has scored twice in a game after doing the same at Southampton and Watford.
Pochettino said before the game that he regarded Alli as "the most important player to emerge in English football in recent years".
And here the £5m signing from MK Dons backed up his manager's confident words with a consummate all-round display crowned by the two towering headers which proved decisive.
Alli received a standing ovation when he was replaced in the closing minutes after showing the quality that will make him an integral part of the future of both Spurs and England.
Chelsea still in pole position
Diego Costa and Pedro had a sharp exchange of views in the first half
Chelsea's perfectionist manager Antonio Conte and his players will be bitterly disappointed they could not achieve Premier League history with a 14th successive win that would have matched the mark set across the 2001-02 and 2002-03 seasons by Arsenal.
However they remain in prime position in the title race.
They still have a healthy five-point lead over Liverpool in second place and have come a long way since their last Premier League defeat at Arsenal on 24 September, a 3-0 loss that left them eight points adrift of then-leaders Manchester City in eighth place.
Conte has transformed the mood around the team and the club and while their superb run may be at an end, this is a team fully equipped to go the distance in the title race.
"A massive victory" - manager quotes
Tottenham boss Mauricio Pochettino: "It is a massive victory, a very important three points to reduce the gap at the top of the table. It was a very tough game, we were playing one of the best teams in Europe, so the value of the victory is massive.
"It makes us very proud and we showed character and were competitive. It is one step forward for the team and is important to keep going. Football is about belief.
"We have shown we can challenge for the big things. We are in a good position, Chelsea is in a very good position, but we are fighting to get points and to reduce the gap above us."
Chelsea manager Antonio Conte: "I saw a game with a great balance. It is not easy to play against Tottenham. But we played with a good personality to create the chances to score a goal, but we could not take them.
"It is strange for us to concede these goals because we are defending well, and they are in a crucial moment. At the end of the first half and then in the second half after we miss the chances to score, but this can happen.
"We must work hard and be pleased with our position in the table, but know this league is tough until the end for the Champions League, for the title."
What's next?
Tottenham play Aston Villa in the FA Cup third round on Sunday before resuming their league campaign at home to West Brom on Saturday 14 January.
Chelsea take on Peterborough in the FA Cup on Sunday before travelling to defending Premier League champions Leicester six days later.
Chelsea's Gary Cahill celebrates after scoring the opener for the leaders
Premier League leaders Chelsea equalled the top flight record of 13 consecutive wins in a single season after overcoming valiant Stoke in a thriller at Stamford Bridge.
An exceptionally entertaining second half witnessed five goals as the Blues were twice made to retake the lead by a Potters side who gave them one of their toughest tests this season.
Gary Cahill gave Chelsea the lead when he headed in shortly before half-time, but Stoke defender Bruno Martins Indi levelled only a minute after the break when he poked in from close range.
Willian handed the Blues the advantage again only for Peter Crouch to level with a sidefoot effort high past Thibaut Courtois.
Stoke barely had time to celebrate, as moments after the restart Chelsea drove towards goal with Willian applying a fierce angled finish.
With five minutes remaining, the Blues all but sealed the three points when Diego Costa - who was magnificent as a target-man - shrugged off the attentions of Martins Indi to fire in the fourth.
Stoke were organised and disciplined at the back and threatened at the other end. In fact, until Cahill's goal they were the better team and looked more likely to score first.
Their spirit was not broken even after Cahill's opener, and seconds after the interval Martins Indi converted his first for the club from Crouch's nod down.
Chelsea's potent attack compensated for their failings at the back, and 11 minutes later Moses and Hazard combined before Willian poked in.
But yet again Stoke, who had not won a league game at Stamford Bridge since 1974, fought back. This time it was Crouch who got on the scoresheet in the league for the first time since May 2015 when he tucked home under pressure.
However, Conte's Chelsea have shown great resolve this season. Just a minute after the second equaliser, Fabregas found Willian in the area and he rifled in from a tight angle.
And with five minutes remaining, Costa finally got his reward for an outstanding display with a close-range strike past the reach of goalkeeper Lee Grant.
Stoke threw everything at them and came away with nothing - but they will take some solace that they were playing the best in the league.
Diego Costa is the top goalscorer in the Premier League with 13 goals this season, more than he managed in the whole 2015-16 campaign
Chelsea equalled a club record as they beat Crystal Palace to secure their 11th successive Premier League win and move nine points clear at the top of the table.
Diego Costa put the Blues ahead with their first attempt on target as he headed in from Cesar Azpilicueta's floated cross.
Marcos Alonso nearly doubled the visitors' lead as he hit the underside of the crossbar with a curling 25-yard free-kick.
Palace's best chances fell to Jason Puncheon, but he headed wide and fired a free-kick narrowly over.
Chelsea also won 11 matches between April and September 2009, with the Premier League record Arsenal's 14-game winning run in 2002.
While it has been a glorious 12 months for Chelsea, the same cannot be said for Palace.
Yes, they reached the FA Cup final, losing 2-1 after extra time to Manchester United, but they have won only six of 36 Premier League games in 2016.
They have kept just one clean sheet in 22 top-flight matches, and are only three points above the relegation zone.
Scott Dann was at fault for Costa's goal - he was caught not watching the ball and failed to get off the ground to challenge.
What's next?
Both sides are in Premier League action again on Boxing Day, with Crystal Palace at Watford in the early game (12:30 GMT) and Chelsea hosting Bournemouth (15:00 GMT).
Chelsea will be without 13-goal top goalscorer Costa as a first-half foul on Joe Ledley saw the Spain striker get booked, his fifth yellow card of the season, and he will now serve a one-match suspension. Team-mate Kante will also be missing as he was also shown a fifth yellow card, following a number of fouls.
Cesc Fabregas has scored more goals against Sunderland (five) than against any other Premier League team
Chelsea moved six points clear at the top of the Premier League as Cesc Fabregas' first-half goal beat a stubborn Sunderland at the Stadium of Light. The Spain international hit before half time to break the Black Cats' resolve, as Antonio Conte's men kept a firm hold on the Premier League summit Cesc Fabregas scored the only goal as Chelsea won at Sunderland to secure a 10th successive top-flight victory and a six-point lead at the top of the Premier League.
Antonio Conte's side took full advantage of Arsenal's 2-1 loss at Everton on Tuesday to secure a firm grip on pole position, Fabregas netting the decisive goal after 40 minutes against a largely toothless Sunderland, although Thibaut Courtois was called upon to make a stunning injury-time save from Patrick van Aanholt to preserve the visitors' advantage.
Chelsea's position contrasts starkly to that which they held exactly one year ago, when a 2-1 defeat away at Leicester City left them one point clear of the relegation zone after 16 matches and proved to be the final game in Jose Mourinho's second stint in charge.
Sunderland were guilty of sitting deep and letting the Blues dictate terms, Fabregas finally making the breakthrough in a tepid first half when he steered a pass from Willian – making his first Premier League start since October 1 with Eden Hazard absent through injury – past Jordan Pickford.
David Moyes' team lacked coherency in attack and, after Adnan Januzaj was denied by Courtois, only the crossbar stopped them slipping further behind to Willian's deflected shot in the 51st minute.
Pickford kept the in-form Diego Costa at bay but Chelsea had done enough to continue their exemplary run of form, while Sunderland remain rooted to the bottom.
Chelsea dominated possession in the first half but struggled to break down a well-organised Sunderland defence, though the hosts were unable to keep hold of the ball when they won it back.
A rare foray forward from Moyes' team ended with Januzaj failing to get enough bend on an 18-yard effort to pick out the top-left corner after 25 minutes.
Chelsea responded with a swift break down the left that saw Marcos Alonso's drilled delivery find Costa, who was unable to cope with the pace on the ball and skewed a volley wide.
Conte's team continued to control proceedings and finally broke through five minutes before half-time when Billy Jones' stray header on the halfway line was pounced upon by N'Golo Kante, enabling Chelsea to surge forward with Willian teeing up Fabregas to guide home from the edge of the box.
Willian was unable to get enough dip on a free-kick from just outside the area in order to test Pickford in first-half stoppage time.
Januzaj was denied by an excellent near-post save from Courtois within two minutes of the restart, but it proved to be a flash in the pan for Sunderland.
Willian's attempt from the right-hand side of the box deflected off ex-Chelsea defender Papy Djilobodji and hit the bar on its way behind, while Pickford got a strong pair of hands down to his left to keep out Costa in the 53rd minute.
Jones was replaced by Donald Love after sustaining an injury in the 59th minute but Sunderland were unable to stem the flow with efforts from Victor Moses and Willian flying wide of the target.
Having spent most of the evening on the back foot, Sunderland almost conjured up an equaliser in the 93rd minute, Courtois springing to his right to palm a swerving effort from former Chelsea man Van Aanholt around the post.
Costa Celebrates: Diego Costa has scored with six of his past nine shots on target in the league
Chelsea moved back to the top of the Premier League and made it nine successive league wins as Diego Costa scored the winner against a stubborn West Brom at Stamford Bridge.
The Spain striker took advantage of a mistake by a hesitant Gareth McAuley in the 76th minute to rob the defender of possession and curl a brilliant left-foot shot past Ben Foster.
West Brom had looked like earning a point after restricting the Blues to just one other shot on target, a 30-yard David Luiz free-kick.
Chelsea also came close through an N'Golo Kante shot that deflected off Pedro and rolled just wide of the post.
The Baggies had early chances through a Chris Brunt shot that fizzed wide and Salomon Rondon shooting across goal.
Chelsea move three points ahead of Arsenal while West Brom stay ninth.
MATCH HIGHLIGHT
Chelsea had scored 22 in their previous eight league victories but looked likely falling victim to a defensive masterclass from Tony Pulis' side until Costa struck.
The Blues had been frustrated by West Brom's compact defence, which hurried and hassled them from the start and pressed high up the pitch, restricting them to speculative shots from long range until McAuley's error.
Diego Costa has scored with six of his past nine shots on target in the league
The 37-year-old Northern Irishman, who had been booked, had plenty of time to clear a hopeful Cesc Fabregas pass down the line but delayed fatally, allowing Costa to force him off the ball and run inside.
It was the 28-year-old's 12th league goal of the season, matching last season's total.
Man of the match - Jonny Evans (West Brom)
West Brom centre-half Jonny Evans was assured throughout, winning 80% of his duels, making five clearances and two interceptions. Unlucky to finish on the losing side.
What's next?
Chelsea go to bottom side Sunderland on Wednesday (19:45 GMT) before a London derby at Crystal Palace on Saturday at 12:30.
West Brom host Swansea on Wednesday (20:00) and then have another home game against Manchester United on Saturday at 17:30.
Chelsea's eighth successive Premier League win cemented their place at the top of the table - but their victory at Etihad Stadium ended in chaos as Manchester City's Sergio Aguero and Fernandinho were sent off in injury time.
Antonio Conte's side delivered an impressive statement of intent as they cut City apart on the break after going behind to Gary Cahill's own goal on the stroke of half-time, when he diverted Jesus Navas's cross beyond Thibaut Courtois.
The game turned on Kevin De Bruyne's 56th minute miss with City in control, crashing Navas's cross against the bar from inside the six-yard area.
Chelsea were level on the hour when Diego Costa outmuscled Nicolas Otamendi to score and they were ahead ten minutes later when substitute Willian raced clear to beat City keeper Claudio Bravo with ease.
Eden Hazard completed a magnificent win for Chelsea with another goal on the break, showing too much pace for Aleksandar Kolarov to wrap up three vital points.
Chelsea's renaissance since their 3-0 loss at Arsenal left them in 10th place eight points behind then leaders City has been hugely impressive - but this is their most powerful statement of the season.
Eight wins from eight and only two goals conceded tells the story and this win against City was the second week in succession they have come from behind to beat a team that could be regarded as realistic title rivals after overcoming Tottenham at Stamford Bridge last weekend.
They were tested here by periods of City domination but showed a ruthlessness to match their steely resilience to tear Pep Guardiola's side to shreds in the closing 20 minutes.
Conte's switch to a three-man defensive system and the rejuvenation of key men such as Costa and Hazard is making this Chelsea side resemble the full title package.
Guardiola's defensive chaos
Manchester City have kept one clean sheet at home in the Premier League this season - in the 4-0 win against Bournemouth - and on this evidence it is easy to see why.
For all City's domination of possession and creation, Guardiola's side have an Achilles heel at the back that was ruthlessly exposed here.
Yes, Kevin De Bruyne should have put the game out of Chelsea's reach but City defence offered the visitors hope throughout and how they capitalised when given the chance.
Guardiola has been linked with defensive reinforcements, particularly Southampton's Virgil van Dijk, and the manner in which they were dismantled here now makes this a matter of urgency.
The jitters started early when John Stones was caught in possession in his own area, while defensive partner Nicolas Otamendi had a nightmare afternoon and was culpable for Chelsea's first two goals from Costa, where he was weak in the challenge, and Willian.
Guardiola gestured in despair towards his central defenders after Willian's goal - his displeasure will surely take the form of more decisive action in January.
An unsavoury end
It is unlikely either Manchester City or Chelsea have heard the last of a shameful conclusion to a high-class game of football as players and officials from both sides became embroiled in ugly scenes.
City's frustration at what they believed were a series of injustices at the hands of referee Anthony Taylor boiled over injury time as Aguero caught Luiz high and late, which happened after the Argentine clashed with the defender at a corner earlier.
Chelsea's Nathaniel Chalobah joined in and was lucky not to see red as a crowd scene developed on the touchline as Fernandinho was sent off for grabbing Fabregas.
Even then, Fernandinho had to be forced to leave the pitch and with the whole situation threatening to go completely out of control, it was fortunate referee Taylor was able to blow the final whistle seconds later.
Gary Cahill's own goal in first half injury time gave Manchester City the half-time lead
It is hard to see how both clubs can escape censure for a failure to control their players.
Man of the match: Eden Hazard (Chelsea)Chelsea's eighth successive Premier League win cemented their place at the top of the table - but their victory at Etihad Stadium ended in chaos as Manchester City's Sergio Aguero and Fernandinho were sent off in injury time.
Enoch Okon
