SAN FRANCISCO -- It took Trevor Story all of four pitches to hit his first home run last season.

This year, it took 11 games.

Either way, the Colorado Rockies shortstop insisted Thursday night, it feels great. Especially when the drought ends against Madison Bumgarner.

Story hit his first home run of the season, and left-hander Chris Rusin rescued injured Jon Gray with 3 1/3 innings of lead-protecting relief, guiding the Rockies to a 3-1 victory over Bumgarner and the San Francisco Giants in the opener of a four-game series.

DJ LeMahieu had two hits and scored a run for the Rockies, who flew into San Francisco having lost three of their past four games after a 5-1 start.

Story's home run, a two-run shot in the fourth inning of a scoreless game, came in his 33rd at-bat of the season. By that point last year, he had blasted seven in a historic rookie-season start.

"I guess you could say it was a relief," the 24-year-old admitted. "But it's just one game. I'm definitely more pumped about the win."

Story's home run to left field came off Bumgarner (0-2), who remained winless in three starts despite striking out eight in six innings. He allowed all three of Colorado's runs on six hits.

"All you can do it control what you can control," Bumgarner said. "You go out there and do your job. And at the end of the day, if you can keep your team in the game and give them a chance to win, that's all you can do. There's no need to be adding any unneeded pressure on yourself."

Staked to a two-run lead by Story's homer in the top of the fourth, Gray threw only five pitches in the bottom of the inning before having to be removed because of an aggravation of a strained right foot he sustained in spring training.

The club's Opening Day starter said he felt a twinge when jumping high to snare an Eduardo Nunez chopper toward the middle of the diamond in the second inning. He considers himself likely to make his next scheduled start.

Rusin (1-0) and three fellow relievers teamed to limit the Giants to four hits the rest of the way, with closer Greg Holland surviving a bases-loaded jam in a scoreless ninth for his sixth save.

"He was the key to the game," Rockies manager Bud Black said of Rusin. "Good work there in middle/long relief. Very efficient. Very integral to this team win."

The Giants put the potential tying runs in scoring position against Holland with one out in the ninth on a grounder off the pitcher's glove by Joe Panik, a slow roller to shortstop by Hunter Pence and a walk to Conor Gillaspie.

But Holland, who hadn't allowed a hit in his first five innings this season, got Nunez to hit a one-hop shot right at second baseman LeMahieu, who turned it into a game-ending, 4-6-3 double play.

"I've been coming here a long time," Black said. "There have been many games like this one."

Rusin was credited with the win after allowing just one run on two hits. He struck out two.

Right-hander Adam Ottavino and lefty Mike Dunn combined to get five outs in the seventh and eighth innings before handing the ball off to Holland for the dramatic ninth.

The Giants' only run came in the seventh inning when Nunez hit a sacrifice fly off Ottavino to score Pence, who reached base on a fielder's choice off Rusin.

The Rockies (7-4) out-hit the Giants 7-5.

Right-hander Neil Ramirez pitched two shutout innings and lefty Ty Blach one in relief of Bumgarner for the Giants, who had won three of their previous four games.

"We owe ourselves two or three comebacks because we've lost some tough ones," Giants manager Bruce Bochy said. "You'd like to think tonight it was going to happen, but we came up short. It's hard to win a ballgame when you score just one run."

Story's homer came with two outs in the fourth and also scored Carlos Gonzalez, who had singled one out earlier.

The Rockies added to their lead in the sixth on singles by LeMahieu, Nolan Arenado and Mark Reynolds, making it 3-0.

NOTES: Giants SS Brandon Crawford joined the team in time to make a late-game, pinch-hit appearance after having driven to Los Angeles overnight to be with his wife's family after the death of his sister-in-law. He grounded out in the eighth inning. ... Rockies RHP Jon Gray was pitching for the first time since donating eight inches of his hair to Locks of Love on Tuesday. ... Giants LHP Madison Bumgarner is winless in his first three starts for the first time since 2011, when he opened 0-6 in eight starts. ... Bumgarner popped up and grounded out in his two at-bats. He is 0-for-5 since opening the season with home runs in his first two at-bats in Arizona. ... Giants RF Hunter Pence went 1-for-4 with two strikeouts on his 34th birthday.