DENVER (AP) -- A late-season surge by Madison Bumgarner is helping to fuel the San Franciso Giants' last-ditch playoff push.
Bumgarner allowed one unearned run in seven strong innings and hit a two-run double, leading the Giants past the Colorado Rockies 9-1 on Friday night for their sixth straight win.
Brandon Belt , Cody Ross and Chris Stewart all homered for the Giants, who closed within six games of NL West leading Arizona with 11 games remaining. The defending World Series champions also gained ground in the NL wild card race, getting within five games of the Atlanta Braves .
"We've got to win every game and hope that they don't to have a chance, but everybody is playing relaxed right now," said Bumgarner. "We've got a good vibe in the dugout and a lot of the pressure that seemed to be on everybody is gone."
Added Giants manager Bruce Bochy : "I've been saying this for the last week - we're hanging by a thread. But we're still alive. We're coming out every day trying to win ball games and hopefully get some help."
There was one glitch on this otherwise hopeful night for the Giants.
Ross, whose fifth-inning solo shot was the 100th homer of his career, left the game with a strained right hamstring in the sixth. He suffered the injury while running to first base after hitting an RBI single.
Bochy said after the game that the team expected Ross to miss about a week but remained hopeful he could return for final week of the season.
"I'm optimistic that it's not as bad right now as I thought, but it is going to take some time," Ross said. "I want to come back as fast as I can and I'll do anything I can to speed it up."
Bumgarner (12-12) allowed six hits in winning his career-best fifth straight. He dropped his ERA in that span to 1.04.
"This kid is just getting better and better," Bochy said. "He's been on a good roll, really hitting his spots with all his pitches. He's got to feel good about how it's gone for him, especially with the rough start that he had."
Alex White (2-2) gave up six runs on nine hits in 5 2-3 innings. White, who has struggled to keep the opposition in the ballpark, gave up two of the Giants' three homers. He has allowed 11 home runs and has an ERA of 8.46 in five starts since coming to the Rockies as a key part of the trade that sent Ubaldo Jimenez to Cleveland.
"It's frustrating," White said. "It's time for this not to happen. There's nothing to do but keep working."
Belt gave the Giants a 2-0 lead in the fourth when he connected for his second homer in as many days. He drove White's first pitch over the center field fence following Aubrey Huff 's one-out single.
The Giants went up 3-0 in the fifth when Ross drove an 0-1 offering from White into the Rockies' bullpen behind the right-centerfield fence for his 14th of the season.
Colorado got on the board in the fifth when third baseman Pablo Sandoval bobbled Dexter Fowler 's grounder for an error, allowing Willin Rosario to score from third base.
But the Giants broke the game open with a three-run sixth, with all the runs coming with two outs.
Brandon Crawford began the rally by drawing a walk. White hit Chris Stewart with a pitch and Bumgarner then doubled off the centerfield wall, scoring Crawford and Stewart.
Ross lined a base hit to left, scoring Bumgarner, but began limping noticably as he ran to first base. The team said Ross strained his right hamstring, and was replaced by pinch runner Andres Torres .
With Aaron Cook making his first relief appearance in eight years in the seventh, the Giants added three more runs on Stewart's two-run homer and Crawford's RBI single.
Notes: Cook had made 184 consecutive starts for the Rockies since his last relief appearance on Sept. 27, 2003. ... Rookie left-hander Eric Surkamp will be going for his third victory in four outings when he starts for the Giants on Saturday against Rockies. It will be Surkamp's first appearance against the Rockies. He'll be opposed by fellow rookie Drew Pomeranz , a winner in his major league debut for Colorado last time out. ... INF Hector Gomez joined the Rockies on Friday after being recalled from the team's Double-A affiliate in Tulsa, where he hit .235 with 14 home runs and 50 RBIs. ... The Giants' winning streak is the longest since a seven-game run from June 22-28.