Arsenal returned to the top of the English Premier League after Jack Wilshere rescued a point for them in a 1-1 draw at West Bromwich Albion, while rivals Tottenham Hotspur suffered a shock 3-0 thumping by West Ham United.
Chelsea relied on two goals in two minutes by substitutes Eden Hazard and Willian late in their match at Norwich City to give them a 3-1 win that lifted them to third in the league with 14 points from seven games, two behind Arsenal and Liverpool.
Surprise package Southampton won again to go fourth, beating Swansea City 2-0 at home, while the day's big upset was at White Hart Lane.
Spurs, who had conceded only twice in the league, leaked three in 13 second-half minutes including an individual effort by Ravel Morrison that West Ham manager Sam Allardyce dubbed 'genius'.
It looked like there was also a surprise on the cards at West Brom, who were up to their old tricks a week after stunning Manchester United 2-1 at Old Trafford when they took a 42nd-minute lead through Claudio Yacob's powerful downward header.
After somehow escaping further damage from more West Brom chances, Arsenal drew level in the 63rd minute when Wilshere made up for his poor performance until that point, smashing in a deflected shot from 20 metres out.
"It was breathless. West Brom showed why they won at Manchester United last week and we had a hell of a task to come back but we showed character and we had chances to go on and win it," the BBC quoted Arsenal manager Arsene Wenger as saying.
"Our position is good because when you look at how we started (a 3-1 defeat at home to Aston Villa) and now we've come out of two away games well so it's a good position to start again after the (international) break."
BOLD DECISION
The point, which puts Arsenal ahead of Liverpool on goals scored, will be all the sweeter for Wenger's side on a day their bitter north London rivals Tottenham lost ground on the leaders after a mauling by West Ham at White Hart Lane.
Allardyce, whose side had not scored away from home and had won just one league game, took the bold decision to start with no recognised striker and the move paid off as defender Winston Reid, winger Ricardo Vaz Te and midfielder Morrison all netted.
While the first two, in the 66th and 72nd minutes set up the victory, Morrison's 79th-minute goal will be the one talked about after the former Manchester United player picked up possession inside his own half, went past Michael Dawson and lifted the ball over keeper Hugo Lloris.
"We thought we'd drop the front man out and play more attacking midfield players from deep running forward," Allardyce, whose club had not won at Spurs since 1999, told Sky Sports.
"You try these things you hope they work ... it's worked and the players have made it work ... We got three different types of goals, we got a set piece, we got a bit of luck and then we got a bit of genius."
FANTASTIC CHANGE
Earlier in the day, Chelsea had grabbed three points at Norwich after it had looked like their fourth-minute lead from an Oscar goal would not be enough when Anthony Pilkington levelled for the hosts in the 68th minute.
The equaliser seemed to shake Chelsea awake and the introduction of Hazard and Willian changed everything.
Chelsea broke quickly after a Norwich corner and Hazard's shot was pounced on by John Ruddy but the ball carried on past the keeper and over the line in almost slow motion on 85 minutes.
Another counter-attack wrapped up the win a minute later as Willian curled in a first-time shot of the kind of class the club will have been hoping for from the 30 million pounds ($48.22 million) they paid for him in the close season.
Chelsea manager Jose Mourinho took the credit for his substitutions after leading his side to their first away win in the league this season.
"When I make a change, the change is always fantastic and the players make it fantastic or make it rubbish - it's up to them," the BBC quoted him as saying.
The only black cloud for Chelsea, and possibly for England ahead of their World Cup qualifiers on Oct. 11 and Oct. 15, was the sight of left back Ashley Cole being substituted in the second half with what looked like a rib injury.
Mourinho said he had in fact taken the England defender off for tactical reasons but that he would be having a scan on the problem which the manager said had been troubling Cole for a while.
Southampton's excellent start to the season continued in a 2-0 home win against Swansea City with Adam Lallana netting in the 19th minute and Jay Rodriguez adding another on 83 minutes.
They are level on 14 points with Chelsea, with Manchester City and Spurs a point behind. Champions Manchester United are ninth with 10 points.