Manchester City slipped to a shock first Premier League defeat of the season when they were beaten 2-1 at Wolverhampton Wanderers on Saturday, while Tottenham Hotspur overcame nine-man Liverpool by the same score thanks to a stoppage-time Joel Matip own goal.
Manchester United's campaign of woe continued with a 1-0 home loss to Crystal Palace but there were no such troubles for Arsenal who, along with Spurs, closed the gap to leaders City to one point with a rampant 4-0 win at Bournemouth.
There were also celebrations for promoted Luton Town, who earned their first success of the season at Everton.
Man City had been imperious this term and made the trip to Wolverhampton having won all six of their opening league games.
A Ruben Dias own goal put Wolves 1-0 up in the 13th minute, but Julian Alvarez levelled with a bending free kick past Jose Sa in the 58th.
Hwang Hee-chan restored the home side's lead on the counter-attack in the 66th by firing into the net from close range, which proved to be the winner.
Having been beaten at Newcastle United in midweek in the League Cup, City have lost back-to-back games in all competitions for the first time since January last season.
"We were well set up but we did not defend properly these situations. They beat us in the one versus one and that is not good and we have to do it properly," City coach Pep Guardiola said.
Liverpool manager Juergen Klopp was equally deflated after his side missed the chance to go top when they conceded in the 96th minute to lose at Spurs after having two players sent off and a goal wrongly ruled out for offside.
Matip turned into his own net to seal the win for Spurs, who moved up to second in the table, after Cody Gakpo had struck in first-half stoppage time to cancel out Son Heung-min's 36th-minute opener.
Liverpool's Curtis Jones was given a straight red card after a VAR review following a tackle on Yves Bissouma in the 26th minute and Diogo Jota was dismissed for a second yellow in the 69th.
Liverpool, who dropped to fourth in the table, had been denied an opening goal for offside when Luis Diaz finished brilliantly, although the referees' body later admitted it was the wrong decision, blaming a "significant human error".
"I never saw a game like this with the most unfair circumstances, crazy decisions," Klopp told Sky Sports.
United slumped to their fourth loss of the Premier League season as an early Joachim Andersen strike gave Palace a 1-0 win at Old Trafford.
Having tasted defeat in their previous home league match, against Brighton & Hove Albion, the hosts were undone again when Andersen arrowed into the top corner in the 25th minute.
With nine points and a minus four goal difference, this is 10th-placed Manchester United's worst-ever start to a Premier League season after seven games. The last time they suffered a worse start to a top-flight campaign was in 1989-90, in the old First Division.
"When we play at home or away and we play Crystal Palace, we have to win," coach Erik ten Hag said. "With all respect ... I understand fans expecting a win and we didn't win. We lost."
Arsenal maintained their unbeaten start to the season on the south coast as Kai Havertz opened his account for the London club and Bukayo Saka, Martin Odegaard and Ben White also scored.
Mikel Arteta's Arsenal, who have yet to concede away from home this season, ended the day in third with 17 points.
Andoni Iraola's winless Bournemouth side dropped into the relegation zone and are 18th with three points from seven games.
Luton have had to wait seven games to get their first Premier League victory that helped them move out of the bottom three.
Everton created 23 chances, but only five of them were on target, as Luton keeper Thomas Kaminski enjoyed his quietest game since his side were promoted back to the top flight.
Boos rang around the ground at the final whistle as Everton's lack of scoring prowess allowed the visitors to hang on for a historic win that lifted them to 17th in the table on four points.
Aston Villa enjoyed a more successful afternoon as an Ollie Watkins hat-trick inspired them to a 6-1 thrashing of Brighton & Hove Albion that moved them up to fifth, three points behind leaders City.
Newcastle United continued their winning streak with a 2-0 victory over Burnley, while West Ham United beat Sheffield United 2-0 at London Stadium.