REUTERS/Jerry Lampen
Andrei Arshavin and Robin van Persie had combined to set up Cesc Fabregas, who gave Arsenal the lead with a low shot in the 36th. But Graziano Pelle's header in the final seconds found da Silva, who volleyed home from close range to stun Arsenal and end the English club's perfect start in Group H.
Arsenal has seven points from three games, while AZ has two.
"This is a morale-boosting draw for us,'' AZ captain Stijn Schaars said.
"You have to be realistic, Arsenal is a very good team with a a lot of quality, so it feels nice to get a draw against them.''
Van Persie got an early chance to put Arsenal ahead from eight metres but the former Feyernoord forward saw his ninth-minute shot blocked by AZ goalkeeper Sergio Romero.
