Walks will haunt, and leadoff walks will haunt absolutely. And for bad teams like the Rockies, walks kill any chance of winning.

Matt Chapman hit a grand slam to help the San Francisco Giants beat the lowly Colorado Rockies 6-3 on Saturday. Chapman connected against Jake Bird (0-1) with one out in the sixth, capping a five-run inning after the Rockies scored three times in the top of the frame.

With the bases still full, the Rockies’ Jake Bird left a sinker right over the heart of the plate. Chapman sent it 402 feet into the Rockies’ bullpen, flipping a one-run deficit into a three-run lead — a lead they’d never lose as Camilo Doval, Erik Miller and Ryan Walker pitched three scoreless innings.