Cuddyer went 3-for-5 with four RBI in the victory and broke an 8-8 deadlock with a leadoff drive off Sergio Romo (4-7) in the ninth.
Cuddyer also had the big blow in Colorado's five-run fifth inning, which slashed the early lead the Giants had built up to 6-5.
The win ended a four-game losing streak for the Rockies. The Giants' had won their previous two games.
DJ LaMahieu drove in two runs for the Rockies. Wilton Lopez (3-4), one of seven pitchers used in the game, picked up the win despite allowing two runs on three hits. Rex Brothers followed in the ninth to pick up his 13th save.