SAN FRANCISCO -- On a night when Colorado failed to capitalize on a few big scoring chances, Clint Barmes once again made the most of his opportunities.
Barmes also hit a sacrifice fly and has driven in four of Colorado's six runs in the first two games of this series.
"What's interesting about the first two games of the series is the number of times in key situations the game has found Clint Barmes," Rockies manager Jim Tracy said. "He's responded big time. Big time."
The Rockies saw runners thrown out at the plate in the ninth and 10th innings before finally breaking through in the 11th on Barmes' hit.
He also hit a two-run single off Tim Lincecum in a victory Monday and now has 23 RBI on the season -- the second most for an eighth-place hitter in the NL this season despite a .219 average.
"I feel like I come up in that situation all the time and I feel like I have failed in most of them," he said. "That's baseball. It's not easy with the pitcher behind you. I'll take every one of those I can get when I get those opportunities."
Santiago Casilla (1-1) retired the first two batters before allowing a single to Miguel Olivo and walking Melvin Mora. Barmes then lined a double just inside the left-field line that scored Olivo with the go-ahead run.
"They had a two-out rally with no one on base and Barmes hits one that lands on the chalk and that's the difference in the game," Giants manager Bruce Bochy said. "He's a threat like all hitters and he's gotten two big hits against us."
Rafael Betancourt (1-1) struck out two in a perfect 10th for the victory. Manuel Corpas got three outs for his fifth save in six chances.
Colorado's bullpen allowed one baserunner in 4 1/3 innings. The Rockies improved to 6-2 in a 12-game stretch against division foes.
"We're playing good baseball," Tracy said. "Our mindset is really good right now. We're in a very good place."
Colorado missed good chances to score the go-ahead run in the ninth and 10th innings. With runners on first and second and two outs in the ninth, Mora lined a two-out single to right. Andres Torres charged and fielded the ball on one bounce. He threw a three-hopper to the plate and Bengie Molina slapped the tag on pinch-runner Johnny Herrera just before he touched home plate to preserve the tie.
Then with runners on first and third and no outs in the 10th, Brian Wilson got Carlos Gonzalez to ground out to third with Barmes holding. Then with runners on first and third, Ryan Spilborghs grounded to third baseman Pablo Sandoval, who easily threw out Barmes at the plate.
The Rockies tied the game at 1 in the seventh when Miguel Olivo singled with one out and went to third on a double by Mora. Barmes followed with a sacrifice fly, but Colorado almost didn't get a run out of it when Aaron Rowand threw out Mora at third base. Olivo crossed home plate just before Sandoval tagged out Mora and plate umpire Ed Rapuano emphatically signaled that the run counted.
That was the only run Colorado scored off Barry Zito, who didn't allow a runner to get into scoring position until Spilborghs' one-out double in the sixth inning. Zito allowed one run and four hits in seven innings, striking out eight.
"I had stuff working good and I was getting out in front," Zito said. "My mechanics were a little more clear today. The curve, you never know when it's going to show up. It did today."
Jason Hammel retired the first nine batters he faced before San Francisco broke through for the first time this series. Torres led off the fourth inning with a drive to right field that bounced into McCovey Cove to give the Giants a 1-0 lead. San Francisco threatened later in the fourth and again in the fifth but was unable to add anything else against Hammel.
He was helped out by a nifty double play turned by Barmes in the seventh. With Buster Posey running from first, Molina hit a grounder up the middle. Barmes fielded it while moving to cover second and tagged out Posey as he slid into the base before throwing out Molina at first.
Hammel allowed one run, seven hits and no walks in 6 2/3 innings, striking out five.
Colorado C Olivo cut his right thumb trying to block a pitch in the fifth inning. He had to have it retaped before the bottom of the sixth to make sure no blood got on the baseball. ... Giants OF Mark DeRosa cut short his rehab assignment at Class A San Jose, saying his left wrist still didn't feel right. He will take a few days off before joining Triple-A Fresno this weekend. ... Colorado optioned RHP Esmil Rogers to Triple-A Colorado Springs after the game and will activate LHP Franklin Morales from the DL before Wednesday's game.