Unai Emery claimed his first victory as Arsenal manager as the Gunners came from behind to beat West Ham, who are still to claim a point under Manuel Pellegrini, 3-1.
Marko Arnautovic put the Hammers ahead after combining with Felipe Anderson after 25 minutes but Arsenal quickly responded through Nacho Monreal.
Arsenal benefitted from a slice of fortune to go ahead in the 70th minute as Alexandre Lacazette's cross deflected in off Issa Diop and Danny Welbeck wrapped up the scoring late on.
Bournemouth came from two goals down to draw 2-2 with Everton in a remarkable clash at the Vitality Stadium that saw both sides finish with 10 men.
The Toffees lost Richarlison for a headbutt on Adam Smith late in the first half but they took control after the break with goals from Theo Walcott and Michael Keane putting them 2-0 up.
The Cherries also had Smith dismissed for bringing down Walcott but they hit back to snatch a draw with a Joshua King penalty and Nathan Ake strike in the last 15 minutes.
The game ended on a sour note as Keane suffered a serious-looking injury.
Harry Maguire hit a superb injury-time winner as Leicester came from behind to beat 10-man Southampton 2-1 at St Mary's Stadium.
Ryan Bertrand had put Saints ahead with a fine strike seven minutes after the restart but the visitors quickly responded through Demarai Gray.
Southampton had midfielder Pierre-Emile Hojbjerg sent off for a second bookable offence 13 minutes from time and defender Maguire made them pay with a fine strike.
Huddersfield held on for a goalless draw against Cardiff after the sending-off of Jonathan Hogg 27 minutes from time at the John Smith's Stadium.
Hogg was dismissed for an apparent headbutt during an argument with Cardiff's Harry Arter but the Terriers survived heavy late pressure to earn a point.