Anthony Rizzo hit two home runs and drove in six to lift the Chicago Cubs to a 13-9 victory over the Pittsburgh Pirates on Sunday.
Rizzo hit a two-run shot in a four-run fifth inning, then capped a five-run sixth with his first career grand slam to seize the lead for Chicago.
The six RBI are a career-high, and it was also the 23-year-old's first multi-homer game.
Pedro Alvarez hit two homers and drove in five for the Pirates, who lost for the 12th time in 15 games.
Jeff Beliveau (1-0) allowed Alvarez's second homer, but recorded the final two outs in the sixth for his first career win.
Jared Hughes (2-2) took the loss after surrendering Rizzo's grand slam.