Liverpool ignited their Premier League season as Mohamed Salah's late goal earned them a stormy 1-0 win over Manchester City to leave Arsenal four points clear at the top on Sunday.
Salah, fresh from his quickfire hat-trick in midweek against Rangers in the Champions League, latched onto a long clearance by goalkeeper Allison in the 76th minute and fired into the net to inflict a first defeat of the season on champions City.
City, who could have gone 16 points clear of their hosts with a win, had a Phil Foden goal disallowed, while Liverpool manager Juergen Klopp was shown a red card for remonstrating with a linesman after a tackle on Salah.
Arsenal made it nine wins from their first 10 games with Bukayo Saka's goal earning them a 1-0 victory at Leeds United.
Mikel Arteta's side have 27 points from 10 games with City and Tottenham Hotspur on 23. Chelsea are in fourth spot with 19 points, with a game in hand, thanks to a 2-0 win at Aston Villa courtesy of a double by England midfielder Mason Mount.
Manchester United are fifth with 16 points from nine games after drawing 0-0 at home to sixth-placed Newcastle United, who have 15.
Despite Arsenal's flying start to the season the popular theory is that relentless City are primed to claim a fifth title in six seasons.
But on a rare off day for City's goal machine Erling Haaland, Liverpool produced a performance that suggests it is far too early to disregard Juergen Klopp's side, who have 13 points from nine games after a rocky start.
Classic matches
Clashes between the sides have produced some classics over the past few seasons and while Sunday's match had plenty of the usual quality, it was a blood-and-thunder affair that occasionally boiled over.
Guardiola was furious when Foden's goal, with the score at 0-0, was ruled out after referee Anthony Taylor checked a pitch-side monitor and decided there had been a foul by Haaland on Fabinho in the buildup.
Salah had been denied by a great save from Ederson but when he found himself one-on-one again he made no mistake. Alisson's quarterback-style clearance was missed by Joao Cancelo and the Egyptian forward ran through to dink a shot over City's keeper.
With tackles flying in Klopp was livid when Salah was not given a foul and he was sent from the technical area.
Klopp was calmer later, admitting that he had probably deserved a red card.
On the result, the German said: "Perfect. Performance, really, really good, in an incredibly intense game.
"We defended at an incredibly high level for 99 minutes almost. They had their moments but especially in the box we did extremely well. This was for us obviously big today. We showed up today and that is all we wanted to do."
The defeat was City's first in 23 away games in the Premier League and Guardiola was left bemused by the decision to disallow Foden's goal.
"The referee said play on, play on, there were a thousand million fouls like this and this one they gave because we scored a goal," Guardiola, who said coins were thrown at him, complained.
"We lost because we make a mistake but this is Anfield."
Lengthy delay
Arsenal's game earlier had suffered a lengthy delay after a power outage at Elland Road.
But they returned after 38 minutes to take the points in a frantic game thanks to Saka's first-half goal from a tight angle following a through pass by Martin Odegaard.
Patrick Bamford missed a penalty for Leeds who suffered their first home loss of the season.
"Big momentum for us, we've won another game. We need to keep this going and today we showed we can win no matter what," Saka said.
Chelsea remain unbeaten in six games since Graham Potter became manager, winning the last five in succession in all competitions.
They were given a helping hand as Villa's Tyrone Mings made a terrible mistake to allow Mount to score in the sixth minute. Mount then sealed the points with a second-half free kick.
In Sunday's other match, Declan Rice's earned West Ham United a point with the equalizer in a 1-1 draw at Southampton who remain in the relegation zone.