Playing against the team he left in the summer to join the Gunners, Eze latched onto a flick from centre-back Gabriel to acrobatically fire the ball home for the winner.
The win takes Arsenal four points clear of Bournemouth, who continued their excellent campaign with a comfortable 2-0 win at home against Nottingham Forest.
Tottenham jumped into third thanks to an emphatic 3-0 win at Everton, with a brace from defender and captain Micky van der Ven and a last minute Pape Sarr strike.
Meanwhile, Liverpool lost for the fourth consecutive game in the Premier League as Brentford beat the champions 3-2 on Saturday.
Less than a month since starting the season with five straight wins, Liverpool’s title defence has come off the rails as the defensive frailties in Arne Slot’s side were brutally exposed by Brentford.
“Today was the worst in my opinion from all the four,” said Slot.
“We didn’t do the basics right in the first half and parts of the second.”
Dango Ouattara hooked in from a long throw after just five minutes to set the tone and Kevin Schade added a second just before half-time at the end of a slick counter-attack that cut the visitors wide open.
Milos Kerkez halved Liverpool’s deficit before Igor Thiago’s penalty restored Brentford’s two-goal cushion.
Mohamed Salah ended his six-game Liverpool goal drought in spectacular fashion late on, but could not dig the Reds out of trouble.
Mbeumo gives United momentum
Manchester United maintained their good recent form with a 4-2 victory over Brighton. It took nearly a year under Ruben Amorim for United to win back-to-back league games but they have now won three in a row after ending the Seagulls’ run of success at Old Trafford.
The Seagulls had won on their previous three visits amid a run of six wins in seven league games against United.
The Red Devils’ attacking additions in the transfer window, Matheus Cunha, Bryan Mbeumo and Benjamin Sesko, are beginning to click.
Cunha curled in his first goal for the club from outside the box before Casemiro’s deflected effort doubled United’s lead before half-time.
Sesko then teed up Mbeumo to fire in at the near post.
Danny Welbeck’s brilliant free-kick and Charalampos Kostoulas’ header set up a nervy finale.
But Mbeumo smashed home his second goal to seal the points in the 97th minute.
“The performance was important but it would not be Manchester United without suffering a bit,” said Amorim.
Chelsea ‘not good enough’
Sunderland’s dream return to the top flight after an eight-year absence goes on after a 2-1 win at Chelsea lifted the Black Cats up to fourth in the table.
Chelsea looked like they would be the side to go second in the table when Alejandro Garnacho drilled in his first goal for the club after just four minutes.
Sunderland levelled midway through the first half when Wilson Isidor bundled in from close range after Chelsea failed to clear a long throw-in.
The visitors comfortably held the Club World Cup winners at bay in the second period before landing the sucker punch on the counter-attack in the 93rd minute when Brian Brobbey teed up Chemsdine Talbi to curl perfectly into the bottom corner.
“We were not good enough and in the Premier League the consequences can be bad,” said Chelsea boss Enzo Maresca.
“If you want to be there (challenging for the title), you need consistency.”
Newcastle beat Fulham 2-1 thanks to captain Bruno Guimaraes’ 90th minute strike at St. James’ Park.
Saka Lukic had cancelled out Jacob Murphy’s opener for the Magpies.
But Marco Silva’s men fell to a fourth consecutive defeat that leaves them hovering just above the relegation zone.
Guimaraes swept home the rebound after Bernd Leno had saved William Osula’s initial effort to propel Newcastle up to 12th.
Elsewhere, Burnley scored a late winner in a 3-2 victory at troubled Wolves, who remain winless in the league this campaign thus far, while a Matty Cash goal was enough for Aston Villa to down Manchester City 1-0.