Pep Guardiola's men now lead Liverpool by a point with seven games remaining for both sides
Liverpool now hold a two-point lead over Manchester City, but the champions have a game in hand.
Chelsea were indebted to Kepa for a series of superb saves that preserved their lead after the break, lifting the sixth-placed Blues within two points of fourth-placed Manchester United.
Blues boss Maurizio Sarri dropped Kepa for Chelsea's midweek 2-0 win over Tottenham as punishment for the Spaniard's refusal to be substituted during last weekend's League Cup final.
Sarri is yet to decide whether to recall Kepa for Sunday's London derby after dropping him for Wednesday's win over Tottenham.
The Spain international said talk of United remaining unbeaten under Solskjaer this season was fanciful given the quality of opposition they must face in the remainder of the campaign.
West Ham roared to a fourth straight English Premier League victory after goals by Robert Snodgrass and Michail Antonio earned a 2-0 win over bottom club Fulham on Saturday.
Fulham captain Tom Cairney's curling cross was headed home by Serbian striker Aleksandar Mitrovic but the linesman's flag was up for offside.
The FA, Wembley's current owners, had come under fire from many within English football for their plans to sell Wembley despite Khan offering to buy the stadium for USD 800 million.
Arsenal have now won six consecutive league matches within a single campaign for the first time since 2016.
Emery's side head to Craven Cottage bidding to extend their winning streak to nine matches in all competitions.
Mitrovic netted his fifth goal of the season with just 12 minutes remaining at Craven Cottage after Andre Gray had put Watford ahead in the second minute.
Fulham has invested heavily in its playing squad, only to start without a point from two games before its first league win on Sunday.
Seri was swayed by the promise of regular first-team football and Chelsea's case was not helped by being still in a state of flux over the status of manager Antonio Conte.