Pep Guardiola got one over his old rival Jose Mourinho as Manchester City edged an absorbing derby clash against Manchester United 2-1 on Saturday to go three points clear at the top of the Premier League.
The victory on their rivals' home turf maintained City's 100 percent start to the season and inflicted a first defeat on United, who looked second best for most of the encounter at Old Trafford.
Arsenal were lucky to escape with three points from a home clash with Southampton as Santi Cazorla held his nerve to score a 94th-minute penalty in a 2-1 win, while a breathless attacking display from Liverpool helped them to a 4-1 victory over champions Leicester City.
Son Heung-min scored twice as Tottenham Hotspur won 4-0 at Stoke City and Watford completed a superb comeback to beat West Ham United 4-2 away.
City's Kevin de Bruyne was at his scintillating best and returned to haunt Mourinho, his former manager at Chelsea, by opening the scoring when he ran onto a flicked header from Kelechi Iheanacho and finished low.
The Belgian, who was deemed surplus to requirements by Chelsea under Mourinho, then created City's second goal when his shot deflected off the post into Nigeria striker Iheanacho's path.
Zlatan Ibrahimovic reduced the deficit just before the break during a breathless first half after City's new goalkeeper Claudio Bravo dropped a high cross at the Swede's feet, one of several errors during an unconvincing debut.
City held firm, however, to take the points as Guardiola landed the first blow in the latest installment of his simmering rivalry with Mourinho.
"We were the team trying to change the result," a defiant Mourinho told reporters. "We had the courage and the honesty and the dignity to go and chase with pride."
Bravo could have given away a penalty with a studs-up challenge on an infuriated Wayne Rooney, while Ibrahimovic had a goal ruled out when he deflected the ball home from a clearly offside position, but United never really got the upper hand in the match.
Arsenal enjoyed much of the possession against Southampton but lacked a cutting edge and needed Cazorla's late penalty to take all three points after Jose Fonte was harshly penalised for tangling with Olivier Giroud.
"He did very well to score because he felt a heavy mental weight for the team," manager Arsene Wenger told reporters. "It's a relief because we missed many chances and they had one or two opportunities having thrown everything forward."
Laurent Koscielny's overhead kick had earlier cancelled out Petr Cech's own goal.
At Anfield, Liverpool delivered a vibrant attacking display to outclass Leicester City, with Roberto Firmino scoring twice and Sadio Mane and Adam Lallana finding the net as the champions' limitations were exposed.
Liverpool took a two-goal lead following first-half efforts from Firmino and Mane, but Leicester halved the deficit when Jamie Vardy capitalised on a mindless pass from Lucas Leiva to tap in past Simon Mignolet.
However, the home side's offensive class told and they restored their two-goal advantage after the break when Lallana rifled a fine shot into the top corner as Leicester's defence were undone, before Firmino added a late fourth from a searing counter attack.
Tottenham's Son scored either side of halftime after fine interplay with the impressive Christian Eriksen as Spurs rediscovered the fluid attacking football that made them such an irresistible offensive threat last season to outclass Stoke.
Dele Alli and Harry Kane opened their accounts for the season after the break as Spurs moved fourth with eight points.
"What was most important was that we started a very difficult run of seven games in 20 matches with a win," said Spurs manager Mauricio Pochettino. "It was the perfect result for us."
Two first-half goals from Michail Antonio put West Ham United in control against Watford, but the hosts drew level when Odion Ighalo and Troy Deeney hit a quickfire double at the end of the first half and Etienne Capoue and Jose Holebas completed a remarkable comeback with second-half strikes.
Crystal Palace got their first win of the season as they beat Middlesbrough 2-1, while Bournemouth beat West Bromwich Albion 1-0 and Burnley and Hull City drew 1-1.