The margin of defeat, though hardly lopsided, was the Giants' largest for a home game this year. San Francisco is 9-4 at AT&T Park, having absorbed each of its previous three home setbacks by two runs.
Other aspects of the game nagged the Giants. Last in the NL in scoring and home runs, they looked especially punchless against Rockies starter Jason Marquis, who entered the ninth inning with a chance to secure his third career shutout. Pablo Sandoval's leadoff home run forced Marquis to settle for his fifth complete game in 10 big league seasons.
The Giants collected five hits for the second successive game, only two of which cleared the infield. They mustered six balls out of the infield overall against Marquis (4-1), who coaxed 14 ground-ball outs.
"A lot of our guys were chasing the pitch down," Giants manager Bruce Bochy said. "That's not going to work against a sinkerballer."
Right fielder Nate Schierholtz concurred.
"He didn't really leave much over the plate at all," said Schierholtz, who went 0-for-4 with a strikeout and three groundouts. "We were chasing bad pitches, including myself."
Not everybody's slumping. Sandoval's batting .500 (11-for-22) during a six-game hitting streak, Emmanuel Burriss has recorded multihit efforts in two of his past three games, Travis Ishikawa is hitting .333 (8-for-24) in his past eight games and Bengie Molina, who twice flied out to deep right field, is always a threat.
But the Giants are 0-for-11 in their past two games with runners in scoring position. Randy Winn and Aaron Rowand are batting .220 and .250, respectively. Fred Lewis, benched Saturday to offer him a mental break and give Schierholtz some activity, is hitting .167 in his last 11 games.
"We do have to get some guys going here," Bochy said. "There's no getting around it."
Winn scolded himself for popping up to second base in the third inning with Burriss on third and one out.
"If I get that run in, it makes [the score] 2-1 and maybe it's a different ballgame," Winn said.
In an ominous development, Winn left the game in the middle of the eighth inning with what he described as a cramp in his right side. Playing left field, Winn initially felt discomfort when he hauled in Spilborghs' seventh-inning drive. Winn tried swinging in the batting cage between innings and felt fine. But the pain returned when he reached to grab Brad Hawpe's long fly in the eighth.
"It was kind of a weird thing. I was just reaching up for the ball," said Winn, who underwent treatment and will be reevaluated Sunday. "I wasn't rotating or swinging or anything."
By contrast, Cain had concrete explanations for his first subpar start of the season.
"I just wasn't locating with my fastball," he said. "I wasn't able to get ahead with it and then put them away with other stuff. So I almost had to work backwards, and sometimes it doesn't work that way."
Nothing worked against Spilborghs, who planted Cain's second pitch of the game in the left-field seats before adding a two-run homer in the fifth.
"The first [pitch] he hit was right down the middle and the next one was a spinning slider," said Cain, who also surrendered Hawpe's sixth-inning leadoff homer.
Cain acknowledged that the Giants' defense muted the Rockies' production. Schierholtz, starting his third game of the year in right field, ran down Ian Stewart's fourth-inning drive near the corner and doubled off Troy Tulowitzki at first base. Burriss went up the middle to snare Todd Helton's third-inning grounder for another out. With Justin Miller pitching in the seventh, Sandoval dove to backhand Garrett Atkins' sharp grounder and made a kneeling throw to first base, where Ishikawa deftly snared the ball on one hop.
"The guys behind me made some huge plays to help me out of innings and keep me in a little longer," Cain said.