SAN FRANCISCO (Ticker) -- Mark Gardner did not flirt with a no-hitter, but he tossed seven masterful innings to help the San Francisco Giants complete a doubleheader sweep of the Colorado Rockies with a 3-0 victory.

Gardner (5-4) followed Livan Hernandez's dazzling performance in the opener of the day-night twinbill by allowing six hits, striking out four and walking one in his return from a brief demotion to the bullpen.

"That was an outstanding performance by Gardy," San Francisco manager Dusty Baker said. "It's hard to believe he hadn't started in a while. He had outstanding rhythm and command."

Hernandez carried a no-hitter into the seventh during a 4-1 victory in the opener, but Gardner, Felix Rodriguez and Robb Nen combined to keep the Rockies off the board in the nightcap.

"I thought Livan had an excellent outing in the first game and Gardy was also excellent," Baker said. "Felix and Robb were unbelievable in the eighth and ninth."

Colorado has scored just one run in dropping four games at Pacific Bell Park this season. The Rockies have been outscored, 18-1 here but have pummeled the Giants by a combined 71-52 in winning five of six meetings at Coors Field this year.

"I think you have to realize when you go to Colorado, you have to check your ego at the door," said Gardner, who was tagged for eight runs and 11 hits over 6 1/3 innings in two relief appearances in Denver. "You just have to outscore them. Here, pitchers have more of a chance to decide things. Luckily, we settled it early today. You have to take more off your breaking stuff to get them to hit ground balls."

Gardner and the Giants got all the offense they needed with one out in the fourth, when J.T. Snow followed Russ Davis' single by belting a 3-2 pitch from Scott Karl (2-3) over the wall in left-center field.

Rodriguez tossed a scoreless eighth and Nen struck out the side in the ninth for his 200th career save, 15th of the season and second of the day.

"It's a wonderful accomplishment," Nen said. "It's nice to have, but I've still got to go out there and save some more games. I didn't throw a whole lot in the first game or in the bullpen. Anytime you face a good team like that you feel good to get the win."

Karl allowed three runs and five hits over 5 2/3 innings for the Rockies, who had won five of six before the sweep.

"Our pitching was great," Rockies manager Buddy Bell said. "Unfortunately, our offense didn't provide us with much. Even in San Diego our bats didn't do much. It's weird. I don't want to take anything away from them, but you have to do better. Our pitching has been too good."

Colorado went down in order in five frames but threatened to score off Gardner in the second. Jeffrey Hammonds led off with a walk but was caught stealing. After Todd Helton popped to first, Jeff Cirillo reached on shortstop Ramon Martinez's error and went to second on Neifi Perez's single to left-center. But Gardner got Scott Servais to ground into a forceout to end the inning.

Jeff Kent flied out to start the fourth, Davis singled and Snow launched his eighth homer to make it 2-0.

"J.T.'s homer off the lefthander was big," Baker said. "Maybe the schedule gods were on our side. They played last night while we had a day off. We were more rested."

Davis again singled with one out in the sixth and went to third on Martinez's two-out base hit to right. Former Giant Julian Tavarez relieved Karl and was greeted by Doug Mirabelli's RBI single to center that capped the scoring.