Olivier Giroud put Arsenal 1-0 up on 28 minutes as he diverted Mesut Ozil’s delivery behond goalkeeper Boaz Myhill.
West Brom hit back before half-time through James Morrison, who got on the end of Chris Brunt’s free kick.
The Baggies’ turnaround was complete when Mikel Arteta deflected James McClean’s cross from the by-line into his own net.
Ozil hit the post for Arsenal in the second half before Cazorla spurned a chance from the penalty spot, with the Spaniard slipping and send his effort over the crossbar.
Chelsea 1-0 Norwich City FT
Jose Mourinho’s Chelsea returned to winning ways as Diego Costa’s goal secured a 1-0 win overNorwich City clinched a fourth win of the season.
Chelsea found the breakthrough on 64 minutes as Costa latched on to Cesc Fabregas’ free kick to cut inside and beat goalkeeper John Ruddy.
Newcastle United 0-3 Leicester City FT
Leicester City’s Jamie Vardy scored for a 10th consecutive Premier League match as his side went top of the table with a 3-0 win at Newcastle United.
Vardy’s goal that equalled Ruud van Nistelrooy’s record came just before half-time when he cut inside before drilling a shot beyond goalkeeper Rob Elliot.
Leonardo Ulloa was on hand to make it 2-0, heading in from Riyad Mahrez’s cross on 62 minutes, and substitute Shinji Okazaki wrapped up the three points.
Watford 1-2 Manchester United FT
Manchester United secured a late 2-1 win over Watford after it looked like Louis van Gaal’s side would have to settle for a Premier League point.
Troy Deeney’s 87th-minute penalty cancelled out Memphis Depay’s first-half goal, only for Bastian Schweinsteiger’s effort to squeeze in off Deeney in the final seconds.
United took the lead on 11 minutes when Ander Herrera whipped in a cross from the right and Depay thumped in a left-footed volley past goalkeeper Heurelho Gomes.
David De Gea could do nothing to prevent Watford from making it 1-1 when Deeney converted from the penalty spot after Marcos Rojo felled Odion Ighalo in the box.
However, in the 90th minute Schweinsteiger’s shot from a tight angle went over the line despite Deeney’s best efforts to clear the ball.
Swansea City 2-2 AFC Bournemouth FT
Garry Monk’s Swansea City battled back from two goals down to claim a 2-2 draw againstBournemouth.
Bournemouth took an early lead at Swansea when Junior Stanislas fed Josh King, who slid the ball past goalkeeper Lukasz Fabianski.
The visitors doubled their advantage through Dan Gosling’s powerful effort, but Swansea swiftly pulled one back as Andre Ayew cheekily backheeled home.
Swansea equalised in the 39th minute when Jonjo Shelvey dispatched from the penalty spot after Ayew was brought down in the box.
Everton 4-0 Aston Villa FT
Romelu Lukaku and Ross Barkley both scored braces to help Everton to a comfortable 4-0 win over Remi Garde’s Aston Villa.
Everton went in front on 17 minutes when Ross Barkley reacted quickest to convert the rebound after Villa goalkeeper Brad Guzan parried Gerard Deulofeu’s shot.
Romelu Lukaku scored his 50th Premier League goal to make it 2-0, heading in from Seamus Coleman’s cross.
Everton were in complete control when Barkley grabbed his second of the game, shooting past Guzan with power.
Lukaku’s second of the game came in the 59th minute with the Belgium international racing on to Barkley’s pass and side-foot into the back of the net.
Southampton 0-1 Stoke City FT
Stoke secured a 1-0 win over away to Southampton as Bojan Krkic grabbed the decisive goal.
The visitors took the lead in the 10th minute when Bojan stole in at the front post to turn home from Erik Pieters’ cross.