The Giants are coming off dropping three of four to NL East-leading Atlanta, including Monday’s 7-6 setback.
San Francisco closer Dustin Hermanson squandered a one-run lead in the bottom of the ninth as the Giants lost for the fifth time in eight games. They are in a virtual second-place tie with San Diego in the NL wild-card race, just a half-game behind the Chicago Cubs.
Hermanson gave up two runs and three hits without recording an out for his second blown save in nine chances.
“I thought we had ‘em,” Giants manager Felipe Alou said. “I’d like to go into the ninth with a one-run lead in every game.”
The Giants hope to make up some ground this week as they play the Rockies and major league-worst Arizona on their six-game homestand.
“Nobody is going to hand it to us, we have to work hard,” said Alou, who called the next six games “a must homestand.”
Brett Tomko, Tuesday’s starter, is coming off his first career shutout in 179 big league starts. The right-hander surrendered just four hits and struck out four while walking one in Thursday’s 5-0 victory at Florida.
Tomko, who is unbeaten in his last five starts, also pitched his first complete game of the season.
“I don’t know if I was craving a shutout, but the win is the most important thing,” said Tomko. “It definitely was icing on the cake. I did a good job of stepping back a second, and not getting too fired up or worked up. I just worried about making pitches.”
Colorado has lost seven straight and 12 of 14, including Sunday’s 8-4 setback to playoff-hopeful Florida.
The Rockies have not won a series since taking three of four in Philadelphia from Aug. 9-12.