Pandya has been out of action since last October after suffering an ankle injury during a 50-overs World Cup match in Pune
Under fire from fans demanding new signings before the transfer window closes on Wednesday, Wenger was given some breathing space after Cazorla drilled in a ninth-minute penalty and Sanchez made it 2-0 in the 39th with a scrambled finish.
Halftime substitute Roberto Pereyra pulled one back for the home side on his Premier League debut when he curled in an unstoppable shot from 15 yards in the 57th minute after a pinball-style ricohet fell kindly for him.