Chelsea maintained its flying start to the Premier League by beating Tottenham 4-2 away to preserve its four-point lead, while Manchester City needed a last-gasp winner to keep the pressure on the European champion.
Substitute Edin Dzeko scored twice in the last 10 minutes - his second coming in injury time - to earn City a 2-1 win at West Bromwich Albion despite playing with 10 men for more than an hour. Second-place Manchester United remained level on points with City thanks to a 4-2 home win over Stoke, with Wayne Rooney scoring twice - as well as an own goal - to open his account for the season.
Chelsea, though, looks unstoppable after recovering from going 2-1 down to end Spurs' four-match winning run. Juan Mata grabbed two goals for the unbeaten visitors.
The buildup to the game had been overshadowed by the continuing fallout from the racism case involving Terry, who on Thursday accepted a four-match ban from the Football Association for racially abusing an opponent during a league game last season. This was the first game of that ban and it was Terry's replacement at center back, Cahill, who put the visitors in front.
A poor headed clearance from Gallas gave Cahill a glimpse of goal and he showed great technique to produce a superb volley that took a slight deflection off Spurs defender Kyle Walker and flew past recalled goalkeeper Brad Friedel. The goal came in the midst of a spell of concerted domination by Chelsea but the team failed to double its lead and was made to pay.
Gallas, who played for Chelsea from 2001-06, made amends for his earlier error by equalizing from barely a yard out after Jan Vertonghen had hooked the ball back into the middle after a searching free kick by Tom Huddlestone. That came just 63 seconds into the second half and Spurs, who were without Gareth Bale after the Wales winger's wife went into labor, went ahead in the 54th.
Aaron Lennon's driven shot from the angle was heading harmlessly wide when Defoe connected with it with a sweet finish that beat goalkeeper Petr Cech at his near post. They were the first goals Chelsea had conceded in the second half this campaign but the classy Mata engineered the turnaround.
He pounced on another unsatisfactory clearance by Gallas to drive home an equalizer from the edge of the area and then ran onto a stunning pass by Eden Hazard to beat Friedel with a curling shot.
Having scored his sixth goal in five games in all competitions, Mata then turned provider by crossing for Sturridge - on as a second-half substitute - to tap in and complete the win.
"We are smooth on the eye but we're a good team and showed good team spirit," Chelsea manager Roberto Di Matteo said.
Over in Manchester, Rooney made up for an early own goal by scoring two at the right end in United's 4-2 victory over Stoke.
Rooney's second goal was his 200th in club football and helped United consolidate second place behind leader Chelsea, after the England striker inadvertently gave the visitors a perfect start at Old Trafford. Rooney headed into his own net in the 11th minute, but then responded with another header for the equalizer after meeting a perfect cross from Robin van Persie in the 27th.
Van Persie then put United ahead in the 44th, before Danny Welbeck made it 3-1 just after the break.
Michael Kightly gave Stoke hope again in the 59th, but Rooney restored the two-goal lead six minutes later to secure the victory.
Elsewhere, Teenage forward Raheem Sterling scored his first Liverpool goal to secure a 1-0 win over Reading and to give manager Brendan Rodgers his maiden home league victory against his former club.
Sterling, at 17 years and 317 days old, became the club's second-youngest Premier League scorer behind Michael Owen.
Liverpool created enough chances to score several more, dominating the first half completely but again struggling to convert opportunities into goals. Sterling finally made the breakthrough in the 29th minute when he received a delicate flick-on by Luis Suarez and raced through the inside-right channel to fire a shot into the far corner of the net.
He had a chance to make it 2-0 shortly after the halftime break when he turned smartly in the penalty area but sent his shot straight at goalkeeper Alex McCarthy.
In other league matches, Fulham blanked Aston Villa 1-0, Swansea doubled up on Wigan 2-1 and West Ham thrashed Southampton 4-1. Arsenal fell to a surprise 1-0 loss at Norwich.
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