A fine header from Alvaro Morata gave Chelsea a 1-0 win over Manchester United at Stamford Bridge as Manchester City stretched their advantage at the top of the Premier League.
For a moment, Chelsea thought they had an eighth-minute lead when Phil Jones volleyed into his own goal under pressure from Alvaro Morata, but referee Anthony Taylor ruled it out for a shove on the defender.
In what was an unexpectedly open start in west London, the visitors soon had a great chance only for Marcus Rashford to head over from Ashley Young's fine cross.
With a little over 10 minutes gone, Chelsea missed a glorious opportunity when Davide Zappacosta's cross reached Tiemoue Bakayoko, who ballooned his effort high over the bar.
Bakayoko was soon in the action again, drilling in a strike that deflected behind, but back came United and Thibaut Courtois saved when Romelu Lukaku turned and shot from the edge of the box.
A fierce Eden Hazard attempt was then parried by David De Gea as Chelsea asked more questions, with Cesc Fabregas heading the rebound wide under pressure from Eric Bailly.
Bakayoko was booked for clattering into Jones in the next Chelsea attack, and as the half-hour mark approached Fabregas looked for Morata, who was unable to steer the cross goalwards.
A lull in pace in the closing quarter of the half was broken when a lovely move involving Hazard and Fabregas ended with a scuffed Zappacosta shot, and at the other end Antonio Valencia won the ball but his cross was cleared.
Five minutes before half-time, Andreas Christensen miscued a good chance from a corner, the ball coming off his shoulder rather than his head and flying over the bar.
Morata controlled the ball on his chest, span and volleyed wide as the second period began, with Phil Jones booked for a hack on Eden Hazard soon afterwards.
When Hazard was then fouled by ex-Chelsea man Nemanja Matic, Chelsea were unable to make the most of the free kick from the right.
But the home side were taking control of the match and, after Hazard had thumped a first-time effort at De Gea, took a deserved 55th-minute lead when Cesar Azpilicueta's cross was superbly headed home by the unmarked Morata.
Shortly after the hour, United boss Jose Mourinho made a double change, bringing on Anthony Martial for Henrikh Mkhitaryan and Marouane Fellaini for Jones.
Fellaini was then caught dawdling on the ball on the edge of his own area but Morata was unable to make the most of it.
Zappacosta made way for Antonio Rudiger as home boss Antonio Conte made his first change, and another Chelsea attack soon followed but Bakayoko's cross from the right was straight to De Gea.
Ander Herrera blasted well wide from the edge of the box following a rare United corner, but Bakayoko had -- and missed -- another good chance when Fellaini was again caught out but he shot wide from the edge of the box.
Hazard tested De Gea once more as United struggled to keep the ball before Mourinho made his last throw of the dice, bringing on Jesse Lingard for Young.
The outstanding Fabregas made way for Danny Driunkwater for Chelsea, and as the game entered its closing stages Rashford saw a powerful strike from the edge of the box zip wide of the post.
Conte then replaced Hazard with Willian, but his side survived a major scare in the 90th minute as Fellaini controlled and volleyed at goal, only to be denied by his Belgium colleague Courtois.
There was still time for Morata to fluff his lines, stumbling when clean through in stoppage time, and for United to win a dangerous 25-yard free kick for a foul on Matic.
But Rashford's deflected strike whistled over and the corner came to nothing as Chelsea cut the gap on their opponents to one point.