The game was decided in the first inning. San Francisco struck for three runs against Yoshinobu Yamamoto and never trailed in a 3-1 victory over Los Angeles at Oracle Park.
Landen Roupp navigated five walks over five innings to earn his fourth win of the season. The right-hander allowed just one hit and one run while striking out seven, carrying a 2.28 ERA. Ryan Walker closed with a perfect ninth inning for his second save.
The Giants loaded the bases in the first and cashed in immediately. Adames scored on Devers' single to right, then Arraez crossed the plate on Schmitt's sacrifice fly to center. Lee capped the rally with an RBI single that brought Chapman home, staking San Francisco to a 3-0 lead.
Yamamoto absorbed the loss despite a strong effort over seven innings. The Japanese ace allowed six hits and three runs while striking out seven, with a 2.48 ERA. Los Angeles managed just one run when Kim's fourth-inning walk brought T. Hernández home with the bases loaded.
San Francisco snapped a one-game losing streak to improve to 9-13. Los Angeles fell to 16-6 despite entering as the division leader.