Mikel Arteta’s side made it four wins from four at the Stadium of Light, with Bruno Guimaraes scoring a spectacular long-range effort before Bukayo Saka converted a late penalty to put the contest beyond the hosts.
Arsenal also had goalkeeper David Raya to thank after he denied Enzo Le Fee from the penalty spot, preserving the Gunners’ control of the game before Guimaraes struck moments later with his first goal for the club.
Saka then wrapped up the victory with the final kick of the match, sending Arsenal three points clear of Manchester City at the top of the table.
City can draw level with the champions if they defeat Manchester United in Sunday’s derby at Old Trafford, but Arsenal’s flawless opening has already created early daylight between themselves and several of their expected title challengers.
Chelsea’s defensive problems again proved costly as Xabi Alonso’s side were held to a 2-2 draw by newly promoted Hull City at Stamford Bridge.
Morgan Rogers gave Chelsea an early lead, but Mohamed Belloumi punished defensive lapses with two goals before half-time to turn the contest around.
Joao Pedro restored parity after the interval, finishing from a Cole Palmer delivery, but the hosts failed to find a winner.
Hull, who remain unbeaten since returning to the Premier League, sit third after continuing their impressive start.
Alonso admitted Chelsea’s matches have become too open, with his side scoring freely but also conceding too often.
The Blues have scored 16 goals and conceded 12 in five matches against top-flight opposition since the Spaniard took charge.
Liverpool also endured a frustrating afternoon at Anfield, settling for a goalless draw against Fulham despite fielding an expensively assembled attack.
Bradley Barcola, Florian Wirtz and Alexander Isak were unable to break down the visitors as sections of the home support expressed their frustration at the final whistle.
Manager Andoni Iraola blamed some of Liverpool’s attacking sluggishness on fatigue following their midweek Champions League engagement against Atletico Madrid.
The draw left sixth-placed Liverpool six points behind Arsenal.
Tottenham’s difficult start continued as they were held 0-0 by Everton, extending their wait for a first Premier League goal of the campaign.
Despite a summer transfer outlay reportedly worth about £300 million, Spurs remain near the relegation places after another blunt attacking display.
Aston Villa are also struggling at the wrong end of the table after suffering a late defeat against Nottingham Forest.
Liam Delap justified Forest’s club-record investment by opening the scoring with a long-range effort before Alysson equalised with Villa’s first league goal of the season.
Igor Jesus struck the decisive goal late on to hand Oliver Glasner his first league victory as Forest manager.
Crystal Palace’s poor start also continued with a 3-2 home defeat to Ipswich Town.
Axel Disasi’s first-half dismissal left Palace vulnerable before Zian Flemming struck in stoppage time to secure all three points for the visitors.
Elsewhere, Brentford maintained their unbeaten start as Kevin Schade scored twice in a 2-2 draw away to Bournemouth.
