Match ends, Chelsea 2, Manchester City 0.
Manchester City were "fantastic" despite suffering a first Premier League defeat of the season at Chelsea, said manager Pep Guardiola.
Chelsea bounced back from the disappointment of losing at Wolves in midweek to end City's 21-game unbeaten league run stretching back to April, and a sequence of 14 unbeaten games away from home.
The defending champions paid for a lack of ruthlessness as they dominated the first half, only to be struck by a smash-and-grab right on half-time as N'Golo Kante fired high past Ederson from Eden Hazard's pass.
Chelsea gained confidence and momentum and improved after the break, securing the win with 12 minutes left when David Luiz's glancing header following a corner bounced in off the far post.
They closed out the win to give Sarri his first triumph over Guardiola, whose team are replaced at the top of the table by Liverpool.
Despite slipping a point behind the Reds, the Spaniard rejected the notion his team had an "off day".
"If you think that, you didn't see the game," he told BBC Sport. "In the first half, we were exceptional.
"In general, we were fantastic. I don't have any regrets. We came and showed we wanted to win. We created chances. They had one in 44 minutes and we conceded a goal. Sometimes that happens.
"It is emotional for me to see these players do what they do every three days. We were outstanding except for five to eight minutes."
- Chelsea and police investigate allegation Sterling was racially abused
- Analysis: What now for Premier League title race?
City pay for lacking killer touch
City's multi-talented squad can cover almost all eventualities, but this was a game in which they sorely missed the marksmanship of the injured Sergio Aguero, and also Kevin de Bruyne's creation.
Guardiola's side were on another level to Chelsea for the first 44 minutes but when chances presented themselves, as they did to both Raheem Sterling and Leroy Sane, there was either hesitation or an inability to provide the final product that proved crucial.
This is not a criticism of either Sterling or Sane but there was a lingering feeling that had the same opportunities fallen to the predatory Aguero, the outcome would have been different.
City could not recover from Kante's sucker punch, and it was Chelsea who were the more dangerous side in the second half.
Guardiola's men must now regroup after a defeat that will be a major disappointment but one hardly likely to set them back for too long.
Kante proves Sarri's point
Kante's outstanding performance, including the opening goal, was vindication for Sarri's decision to play him in a new role this season.
Sarri has been questioned for his decision to use Jorginho as the hub of his team while pushing Kante into a more advanced role out on the right - why have the player many regard as the finest holding midfield player in world football and not utilise him there?
Sarri has stuck to his guns and this was a game - and performance by Kante - that added significant weight to his argument.
The World Cup winner was magnificent, typically tireless but also getting into forward positions, most decisively when he arrived on the end of Hazard's inviting pass to power a finish past Ederson that gave the Brazilian no chance.
It is certainly not the end of the argument, but evidence Sarri can use that he is coming up with the right formula.
Man of the match - N'Golo Kante
'We deserved to win' - what they said
Chelsea boss Maurizio Sarri: "I am very happy with the win because it is not very easy to win against Manchester City or Pep Guardiola. I am happy with the mentality of the team in this match.
"It is difficult for us to find motivation but when we have it, we are a very strong team. Today we played with a very good level of application, determination and the right level of aggression.
"My players have to continue like this. We started well in the second half and in the end we deserved to win."
Manchester City manager Pep Guardiola: "At this level and in the Champions League, the quality of the opponents means they only need a half a chance to score. That was the reality."
Fortress Stamford Bridge - the stats
- Chelsea are unbeaten in 12 Premier League games at Stamford Bridge (W7 D5), their longest run without a home league defeat since a 21-game streak ending in August 2015.
- City suffered their first Premier League defeat in 22 games, since a 3-2 loss to Manchester United in April. They also conceded more than one goal in a Premier League game for the first time since that match.
- This was Sarri's first victory over Guardiola, ending a run of three defeats against the Spaniard in all competitions (W1 L3).
- Guardiola has lost three league games against Chelsea, more than against any other side as a manager.
- Kante's opening goal came from Chelsea's first shot of the match in the 45th minute, the longest they have had to wait for a shot in a league game at Stamford Bridge since 2006-07.
- With four 'goal involvements' in the Premier League this season (2 goals, 2 assists), Kante has already equalled his combined tally from his previous two top-flight seasons with Chelsea (2 goals, 2 assists in 69 games).
- Hazard has provided an assist in three consecutive Premier League games for the first time since December 2014.
- Hazard has now assisted a league-high eight goals in the Premier League this season - double the tally he assisted in 34 appearances last season (4).
Both teams play in Europe in midweek, completing groups from which they have already qualified. City host Hoffenheim in the Champions League on Wednesday and Chelsea have a Europa League trip to Vidi on Thursday.
In the Premier League, City's home game against Everton is next Saturday's 12:30 GMT kick-off, while Chelsea travel to Brighton at 13:30 on Sunday.
- 30David Luiz
- 5JorginhoBooked at 63mins
- 17KovacicSubstituted forBarkleyat 65'minutes
- 11PedroBooked at 80mins
- 10E HazardSubstituted forGiroudat 90'minutes
- 22WillianSubstituted forLoftus-Cheekat 75'minutes
- 20Bernardo Silva
- 21SilvaSubstituted forGündoganat 68'minutes
- 26MahrezSubstituted forFodenat 84'minutes
- 19SanéSubstituted forGabriel Jesusat 53'minutes
- 33Gabriel Jesus
- Michael Oliver
- Shots on Target
Second Half ends, Chelsea 2, Manchester City 0.
Attempt missed. Kyle Walker (Manchester City) right footed shot from outside the box is high and wide to the right. Assisted by Ilkay Gündogan following a corner.
Corner, Manchester City. Conceded by Kepa Arrizabalaga.
Attempt saved. Gabriel Jesus (Manchester City) right footed shot from the centre of the box is saved in the bottom right corner. Assisted by Ilkay Gündogan.
Substitution, Chelsea. Olivier Giroud replaces Eden Hazard.
Attempt missed. Fernandinho (Manchester City) right footed shot from outside the box is close, but misses to the left following a corner.
Attempt blocked. Raheem Sterling (Manchester City) left footed shot from the left side of the box is blocked.
Corner, Manchester City. Conceded by Marcos Alonso.
Attempt missed. Gabriel Jesus (Manchester City) left footed shot from the centre of the box is close, but misses to the left. Assisted by Raheem Sterling with a cross.
Attempt missed. Ross Barkley (Chelsea) header from the centre of the box misses to the left. Assisted by Pedro with a cross.
Substitution, Manchester City. Phil Foden replaces Riyad Mahrez.
Attempt saved. Aymeric Laporte (Manchester City) left footed shot from more than 35 yards is saved in the bottom left corner. Assisted by Kyle Walker.
Pedro (Chelsea) is shown the yellow card.
Fernandinho (Manchester City) wins a free kick in the defensive half.
Foul by Ruben Loftus-Cheek (Chelsea).
Goal! Chelsea 2, Manchester City 0. David Luiz (Chelsea) header from very close range to the top right corner. Assisted by Eden Hazard with a cross following a corner.
Corner, Chelsea. Conceded by Riyad Mahrez.
Attempt blocked. Ross Barkley (Chelsea) right footed shot from outside the box is blocked. Assisted by Ruben Loftus-Cheek.
Foul by John Stones (Manchester City).