SAN FRANCISCO — Albert Pujols burst out of his power slump with two homers, and Chris Duncan drove in the go-ahead run with a two-out double in the seventh inning of the St. Louis Cardinals’ 6-2 victory over the San Francisco Giants on Saturday night.

Pujols hit homers in the second and ninth innings for his third multihomer game of the season. The defending National League MVP had just one homer in his previous 15 games, driving in just six runs during the stretch — a bonafide drought by his formidable standards.