Michu fires in Swansea’s second goal
Michu enhanced his ever-growing reputation with two late goals to give Swansea City a stunning victory, while Everton continued its good run against champions Manchester City leaving with a share of the points in a 1-1 draw.
The Spanish striker broke the deadlock with two minutes left, curling the ball around Wojciech Szczesny after playing a neat one-two with Luke Moore.
Nathan Dyer's persistence then gave Michu a clear run at goal and another composed finish gave Szczesny no hope.
Gervinho wasted Arsenal's best chance when he made a complete mess of a free header straight in front of goal.
At the Etihad Stadium, Manchester City continued their unbeaten start to the Premier League season but had to settle for a point against a battling Everton side.
Everton took the lead when Fellaini turned in Leighton Baines' cross after Joe Hart saved his initial header.
Carlos Tevez levelled from the spot after Fellaini dragged down Edin Dzeko.
City had the better of a tight second half but struggled to create chances and Everton almost snatched victory with Nikica Jelavic's free-kick.
The point is enough to send Roberto Mancini's side to the top of the Premier League on goal difference, at least until Manchester United play Reading in Saturday's late game.
In other games, Tottenham beat Fulham 3-0, QPR drew 1-1 with Aston Villa and West Brom suffered a 1-0 home defeat to Stoke.
West Ham 3 - 1 Chelsea
Arsenal 0 - 2 Swansea
Fulham 0 - 3 Tottenham
Liverpool 1 - 0 Southampton
Man City 1 - 1 Everton
QPR 1 - 1 Aston Villa
West Brom 0 - 1 Stoke