Giants 6, Nationals 1: Brandon Belt drove in three runs and Madison Bumgarner threw his second career complete game as host San Francisco snapped a four-game losing streak to Washington.

After losing the series opener 14-2, the Giants rebounded from their largest margin of defeat this season to remain tied with the Dodgers atop the National League West. Washington’s lead over Atlanta in the NL East fell to 4 1/2 games.

Bumgarner (13-7) allowed five hits with one walk and six strikeouts on 108 pitches for the Giants, who won for the eighth time in 12 games.

Nationals starter Jordan Zimmermann (9-7) gave up two runs on eight hits over 5 2/3 frames as he failed to pitch at least six innings for just the second time in 24 starts this season.

The Giants grabbed an early lead in the second, when Hunter Pence led off with a single and scored when Belt crushed a double to deep left field before being thrown out trying to reach third.

Belt’s baserunning came into question again in the sixth after Pablo Sandoval walked and Pence singled. Belt hit a shot off the right field wall that scored Sandoval, but he was thrown out trying for a double.

The Nationals cut the deficit to 2-1 in the seventh when Adam LaRoche’s infield single plated Jayson Werth, who tripled to lead off the inning.

San Francisco pulled away with four runs in the eighth on Sandoval’s sacrifice fly and RBI singles by Belt, Brandon Crawford and Angel Pagan. Belt had three hits and is batting 15-for-30 in his last nine games.

Pence and Marco Scutaro added three hits apiece for San Francisco, which won despite going 4-for-10 with runners in scoring position.

GAME NOTEBOOK: Sandoval went 0-for-2 in his first start since landing on the disabled list on July 24 with a strained hamstring. …OF Mike Morse (thumb) was held out of the Nationals lineup, but he expects to return for Wednesday's series finale. … The Giants placed RHP Brad Penny on the 15-day disabled list with a right shoulder impingement and recalled RHP Dan Otero from Triple-A Fresno. … Nationals SS Ian Desmond (oblique) could be activated from the disabled list Friday.