Eden Hazard and close-season signing Willian came off the bench to score decisive goals as Chelsea won 3-1 at Norwich City to climb to third place.
The visitors took a fourth-minute lead when Oscar drilled home from Demba Ba's lay-off, but Norwich gradually took the upper hand and equalised in the 68th minute.
Martin Olsson's deep left-wing cross was headed back across goal by Ricky van Wolfswinkel and Anthony Pilkington ghosted in behind David Luiz to glance a deft header past Petr Cech.
Chelsea manager Jose Mourinho reacted by sending on Hazard and Willian, and it proved a masterstroke.
Hazard completed an 85th-minute counter-attack with a low shot that squirmed beneath John Ruddy to put Chelsea ahead before Willian curled home a glorious left-foot shot a minute later to claim his first goal for the club.
The two late goals elevated Chelsea to third place, two points beneath Arsenal and Liverpool, while results later in the day saw Norwich slip into the relegation zone.
Jack Wilshere sent Arsenal back to the top of the English Premier League table with a second-half equaliser in an entertaining 1-1 draw at West Bromwich Albion on Sunday.
Bidding to follow up last weekend's shock victory at Manchester United, West Brom took a 42nd-minute lead at The Hawthorns when Claudio Yacob converted Morgan Amalfitano's right-wing cross with a near-post header.
Former Arsenal striker Nicolas Anelka spurned two glorious opportunities to double the hosts' lead, fluffing his lines from Saido Berahino's low cross and then curling wide with only Wojciech Szczesny to beat.
He was made to pay for his profligacy in the 63rd minute when Wilshere met Tomas Rosicky's lay-off with a crisp drive that took a deflection off Jonas Olsson and flashed past goalkeeper Boaz Myhill.
Myhill prevented Olivier Giroud from claiming a late winner, but the draw was enough to take Arsene Wenger's side above Liverpool on goals scored, while Steve Clarke's West Brom remain 12th.
Hammers sink Spurs
Tottenham Hotspur could have moved level on points with the leaders, but they were dealt a stunning 3-0 home defeat by London rivals West Ham United.
After a quiet first half, Spurs appeared to be hitting their stride in the second period when Winston Reid put West Ham ahead in the 66th minute, smashing home after Kevin Nolan had inadvertently blocked his header.
Ricardo Vaz Te added a second goal six minutes later, the ball ricocheting off his thigh and into the net after Hugo Lloris blocked his initial attempt, before Ravel Morrison completed the scoring with a fine solo goal.
The result leaves Spurs in sixth place, three points below Arsenal and Liverpool, while West Ham leap out of the bottom three to 13th.
Southampton continued their fine start to the season by winning 2-0 at home to Swansea City, which sent Mauricio Pochettino's side to the dizzying heights of fourth place.
Saints captain Adam Lallana broke the deadlock in the 19th minute when he polished off a fine pass from Steven Davis.
Goalkeeper Artur Boruc thwarted Swansea on several occasions as the visitors pushed for an equaliser, before Jay Rodriguez made the game safe with seven minutes remaining.