SAN FRANCISCO -- Madison Bumgarner took another step toward cementing his status as the best-hitting pitcher in the majors.
The Giants' three-time All-Star was still more pleased with what he did on the mound than at the plate.
Bumgarner hit a home run and pitched seven innings for his third consecutive win, and San Francisco beat the Oakland Athletics 2-1 on Saturday.
"He's a threat up there," Giants manager Bruce Bochy said. "What's impressive is he's made himself into a pretty good hitter, too. It's not just the long ball. It just goes to show you how a pitcher can help themselves besides throwing the ball."
Bumgarner -- a Silver Slugger award winner in 2014 -- homered on a 3-2 pitch from A's starter Chris Bassitt (0-3) in the third. It was Bumgarner's third home run this season and ninth of his career.
Bumgarner (11-5) also struck out seven while working past the sixth inning -- something he failed to do in each of his previous three starts.
"Today it wasn't looking real good early but we were able to get some quick outs and make some pitches," Bumgarner said. "That's definitely more satisfying for me."
Matt Duffy added a tiebreaking single in the sixth while helping the defending World Series champs to their 10th victory in 11 games.
Sergio Romo pitched the eighth and Santiago Casilla worked the ninth for his 25th save.
Joe Panik added two hits and scored a run for San Francisco.
Ben Zobrist had three hits and scored the A's only run in the fourth inning.
The A's have lost four of five to drop 11 games under .500.
"We needed one big hit and never got it," Oakland manager Bob Melvin said. "The best swing of the day was the one Bumgarner hit."
The Giants went into the game leading the NL in scoring but had few opportunities against Bassitt and two relievers.
Bumgarner's home run put San Francisco up 1-0 and was the first by a pitcher against the A's since Baltimore's Dave McNally homered off Ken Holtzman in 1972.
"I fouled the previous pitch off my knee so I just tried to stay inside it a little more and was able to make an adjustment," Bumgarner said.
Oakland backup catcher Josh Phegley tied it with an RBI double in the fourth.
Panik hit a two-out double in the sixth and scored on Duffy's single to put the Giants up 2-1.
Bassitt, called up from minors before the game to make the start, allowed five hits in six innings with four strikeouts.
Athletics: RHP Angel Castro was optioned to Triple-A Nashville to make room for Bassitt. ... Closer Sean Doolittle (strained left shoulder) threw off flat ground and will pitch a bullpen session Thursday. ... Leadoff hitter Billy Burns did not start after fouling a ball that hit him in the groin on Friday. He grounded out as a pinch hitter in the seventh.
Giants: Bochy said leadoff hitter Nori Aoki (broken leg), who went hitless in a rehab game Friday, needs more at-bats in the minors before rejoining the big league club. ... RHP Tim Lincecum has resumed playing catch and throwing but has yet to get back on a mound. Lincecum, who has been sidelined with a bruised forearm, was recently diagnosed with degenerative hip disorder in both hips.
Athletics: RHP Kendall Graveman (6-6) has a 2.76 ERA in 11 starts since being called back up from the minors, but has dropped his last two decisions.
Giants: RHP Tim Hudson (5-8), who pitches the series finale Sunday, was a sixth-round draft pick by Oakland in 1997. He'll be facing his former team for just the third time in his career.