"Matt Cain finally jumped aboard the Giants' magnificent starting rotation merry-go-round Saturday, and he did so with a vengeance.

Cain, who was the club's only starter without a victory in April, took advantage of an early cushion and allowed only one hit in eight shutout innings as the Giants beat Colorado 6-1 at AT&T Park.

Cain (1-1) had not pitched poorly in his first four starts, giving up three earned runs in each of his first two outings and two in each of his next two. But his fifth start was more in line with the kind of performances the Giants had received from Tim Lincecum, Barry Zito and Jonathan Sanchez throughout much of the first month.

Cain retired the final 15 batters he faced in a 123-pitch effort in which he walked three and struck out eight. The only hit against him was a leadoff double by Troy Tulowitzki in the fourth inning. It turned out to be the last batter the right-hander would allow to reach base.

Cain said he hadn't felt pressure to hold up his end of the Giants' starting dominance but was glad to be back as one of the pack.

"Zito threw great (Friday) night, and you want to back that up," he said. "Timmy did the same thing the day before that. Everybody's been throwing the ball really well, and I'm just happy we can feed off each other." "