Marcos Alonso pounced on Eden Hazard's cross to settle the game in the second half after the visitor fought back from two down but spurned further chances in a game that lifted Chelsea joint top of the table alongside Tottenham Hotspur, who beat Fulham 3-1, and Bournemouth, who won 2-1 at West Ham United
A second successive Chelsea win under Maurizio Sarri, 3-2 over an Arsenal side who have suffered back-to-back defeats under Unai Emery, gave both managers a crash course in the unpredictability of the Premier League Saturday.
Marcos Alonso pounced on Eden Hazard's cross to settle the game in the second half after the visitor fought back from two down but spurned further chances in a game that lifted Chelsea joint top of the table alongside Tottenham Hotspur, who beat Fulham 3-1, and Bournemouth, who won 2-1 at West Ham United.
Elsewhere, Leicester City and Everton posted their first victories, against Wolverhampton Wanderers and Southampton respectively, while the day's other game between league newcomers Cardiff City and Newcastle United ended goalless.
That sort of scoreline was never a possibility at Stamford Bridge, where the visitor raced into the lead through Alvaro Morata and Pedro, but were lucky to go into the interval level after Arsenal squandered opportunities either side of goals from Henrikh Mkhitaryan and Alex Iwobi.
Chelsea brought Hazard off the bench midway through the second half and were rewarded when he broke free on the left and crossed for Alonso to shoot low under Petr Cech's body.
First goal in August for Harry Kane ☑️— UEFA Champions League (@ChampionsLeague) August 18, 2018
First league goal for Spurs for Lucas Moura ☑️
Another wonderful free-kick from Kieran Trippier ☑️
A good day for Tottenham as they beat Fulham 3-1#UCL pic.twitter.com/YHqN3UT3Mf
In the week that Spurs apologised to their supporters for further delay in their return to White Hart Lane, their victory gave a reminder of how accustomed they have grown to Wembley, with two of their England internationals leading the way after Fulham equalised Lucas Moura's opener.
Kieran Trippier replicated his free-kick goal for England in the World Cup with another superb strike before Harry Kane rounded off an impressive win by scoring his first ever Premier League goal in August.
Bournemouth took full advantage of comic home defending to strike twice in six second-half minutes through Callum Wilson and Steve Cook, inflicting Manuel Pellegrini's second successive defeat since returning to the Premier League with West Ham United.
Everton also changed managers in the summer but Marco Silva has enjoyed a more promising beginning and secured a 2-1 win in his first home game with new signing Richarlison scoring his third goal in two games since his move from Watford.
The Brazilian only managed five in total last season but looks a different proposition since reuniting with his former manager.
Richarlison headed Everton's second after former Southampton forward Theo Walcott had opened the scoring after a well-worked free-kick move from Leighton Baines and Morgan Schneiderlin.
Another Brazilian, Newcastle's Kenedy, had a less memorable day, missing a stoppage-time penalty which would have given the 10-man visitors victory at Cardiff City, who were playing their first home Premier League game for four years.
Cardiff's hero was keeper Neil Etheridge, who saved his second spot-kick in successive games to spark wild celebrations at the Cardiff City stadium.
Leicester also ended their 2-0 win over Wolves with 10 men after their England striker Jamie Vardy was dismissed for a reckless tackle on Matt Doherty.
The challenge that was all the more needless because Leicester were in control through a Doherty own goal and a strike from James Maddison, his first Premier League goal since his 24m pound ($30.6m) move from second-tier Norwich City.
Maurizio Sarri says his team did well for 75 minutes with the last 15 minutes of the first half described as "horrible". He says his side were not able to press in that period but they found an answer in the second half. #CHEARS— Chelsea FC (@ChelseaFC) August 18, 2018
Cardiff 0 Newcastle 0
Chelsea 3 (Pedro 9, Morata 20, Alonso 81) Arsenal 2 (Mkhitaryan 37, Iwobi 41)
Everton 2 (Walcott 15, Richarlison 31) Southampton 1 (Ings 54)
Leicester 2 (Doherty 29-og, Maddison 45) Wolves 0
Tottenham 3 (Moura 43, Trippier 74, Kane 77) Fulham 1 (Mitrovic 52)
West Ham 1 (Arnautovic 33-P) Bournemouth 2 (Wilson 60, Cook 66)
Brighton v Man Utd, Burnley v Watford and Man City v Huddersfield