Updated

It has been a sparkling turnaround for Madison Bumgarner at AT&T Park.

Bumgarner hurled the second complete game of his career as the San Francisco Giants downed the Washington Nationals, 6-1, in the middle test of a three- game set.

Bumgarner (13-7) surrendered a run on five hits and one walk while fanning six. He is 8-1 in 11 assignments at AT&T Park this year and lowered his ERA to an NL-leading 1.87 at home.

"It started with him with the job he did," Giants manager Bruce Bochy said. "We needed a well-pitched game and he's as good as anybody."

The 23-year-old sidewinding left-hander, who was 1-8 with a 5.02 ERA over his first 16 starts in San Francisco, has gone 16-2 with a minuscule 1.84 ERA over his last 21 home tilts.

"He stays out of the middle of the plate, that's what he does really good," Nationals manager Davey Johnson said.

Brandon Belt tallied three hits and had his seventh career three-RBI game for the Giants, who have won eight of their last 12 contests. In his first start since coming off the disabled list Monday, Pablo Sandoval had an RBI and run scored.

Jordan Zimmermann (9-7), 4-0 with a 0.87 ERA over his last five road starts coming in, allowed two runs on eight hits and two walks over 5 2/3 frames for Washington, which has dropped two of three on the heels of an eight-game winning streak.

Jayson Werth led off the seventh with a triple before Adam LaRoche's RBI single cut the San Francisco deficit in half, 2-1, but the Giants surged ahead following a four-run eighth.

Melky Cabrera doubled to start the frame and moved to third on a wild pitch. After Buster Posey walked, Cabrera scored on Sandoval's sacrifice fly to center field.

Three straight singles by Hunter Pence, Belt and Brandon Crawford plated two more runs before Bumgarner struck out. Angel Pagan then beat out an infield single to score another run and make it 6-1.

The Giants opened the scoring in the second and added another run in the sixth.

Pence singled to begin the second and Belt brought him home with a double to deep left. In the sixth, Sandoval worked a one-out walk and moved to second when Pence singled before Belt banged a single off the top of the bricks in right field to plate Sandoval for a 2-0 Giants lead. Belt was thrown out at second on the play.

Game Notes

San Francisco was 4-for-10 with runners in scoring position and left eight men on base, while Washington finished 1-for-5 with RISP and stranded five ... Bumgarner lowered his season ERA to 2.97.