ARSENAL'S clash against London rivals Chelsea is the north London side's last chance to stop the Premier League leaders from running away with the title, former France winger Robert Pires has said.

Arsenal, in third, failed to capitalise on Chelsea's draw at Liverpool as they lost at home to Watford on Tuesday and will go 12 points behind the table-toppers if they are beaten at Stamford Bridge.

"I think this is the last chance for Arsenal and it is a final for the Premier League," Pires, who enjoyed a highly-successful seven-year spell at Arsenal, told Sky Sports.

"If Chelsea beat Arsenal, I think the Premier League is totally finished. Chelsea have played well for four months but if Arsenal beat Chelsea at Stamford Bridge, anything is possible.

"Arsenal will be more concentrated and more focused and when I see (Alexis) Sanchez and (Mesut) Ozil, they can do something at Stamford Bridge."

Pires believes the battle between Arsenal defender Laurent Koscielny and Chelsea striker Diego Costa will influence the outcome of the match.

"Koscielny is a good defender, maybe one of the best defenders in the Premier League," Pires added.

"He's very strong, he's very fast and everybody knows Diego Costa loves to fight, he has scored a lot of goals. So, maybe this is the key for the game."