SAN FRANCISCO (AP) -- Except for about 30 friends and family in the stands, Sacramento native Vance Worley silenced the announced crowd of 41,794 at AT&T Park with the best performance of his career.
''Just glad I gave them something fun to watch,'' said Worley, who didn't grow up a Giants fan but heard ''a lot of lip'' from friends after coming up in the Phillies organization.
Worley sure seems to bring his best against San Francisco.
Worley (4-1) struck out three and walked one in an efficient 100-pitch outing. His only other complete game came in a 7-2 win over the Giants on July 26, 2011, in Philadelphia.
Four players drove in a run off Bumgarner (12-8) in the first, and Josh Harrison hit his seventh homer in the second to provide all of Pittsburgh's pop.
Worley worked over batters the rest of the way to hand San Francisco its fifth straight loss and 12th shutout this season.
The right-hander was acquired from Minnesota on March 25 for a player to be named or cash. He spent time in extended spring training and with Triple-A Indianapolis before being thrust into Pittsburgh's rotation because of injuries.
Worley has made the most of his opportunities in the majors. He has a 2.54 ERA in eight appearances this season, including seven starts.
''He had to fight back. He had to make some adjustments,'' Pirates manager Clint Hurdle said. ''He's been focused. He's been prepared. He's not doing anything he hasn't done before. His confidence is playing. The command is what's showing up.''
Worley didn't allow a baserunner until Pablo Sandoval singled for the first of his two hits. Gregor Blanco hit a swinging bunt single in the sixth before being nabbed trying to steal second. And Hunter Pence's two-out triple in the ninth was the only other hit off Worley.
The Giants, who were just swept in a three-game home series by the Dodgers to fall out of first place in the NL West, were counting on their All-Star pitcher to help wash away their woes.
Instead, Bumgarner gave up five runs and six hits in four innings. He had allowed one run in 14 innings since the All-Star break and was coming off his best start of the season.
All that evaporated in a 41-pitch first. He allowed three hits, two walks and committed one of two San Francisco errors in the inning when he misfired to second trying to pickoff Andrew McCutchen.
Pirates: Left fielder Starling Marte can come off the concussion list Wednesday but likely won't resume baseball activities until a few days after that.
Giants: First baseman Brandon Belt passed his concussion test, resumed working out and is expected to return early in the team's 10-game road trip that begins Friday at the New York Mets. ... Backup catcher Hector Sanchez failed his concussion test and said he will be out least another three days. ... Center fielder Angel Pagan (back) will go through his pregame workout routine Tuesday in Arizona, and if everything goes well the Giants will set a date for his rehab assignment.
Pirates: LHP Francisco Liriano (2-7, 4.18 ERA) looks for his second straight victory.
Giants: RHP Tim Hudson (8-7, 2.65 ERA) tries to stop his three-game home losing streak.
TURN TWO: The Pirates helped Worley out with two double plays, including a spectacular turn by second baseman Neil Walker in the fourth. Walker grabbed shortstop Jordy Mercer's glove scoop barehanded while falling, turned and threw to first to get Michael Morse. ''I knew I was going to have to bare-hand the ball, but I just didn't know where it was going to be,'' Walker said. ''It was kind of just instinctual.''
After starting the season 22-9 at home, the Giants are 6-20 in San Francisco since and 28-29 overall. ''This is kind of where you make your money at,'' said Bumgarner, who is 4-6 at AT&T Park this season. ''It's really weird.''