SAN FRANCISCO — Madison Bumgarner pitched a five-hitter and Brandon Belt had three hits and three RBIs, leading the San Francisco Giants to a 6-1 win over the Washington Nationals on Tuesday night in a matchup between NL division leaders. Bumgarner (13-7) struck out six and walked one in his second complete game this season. Hunter Pence and Marco Scutaro, both acquired before the July trade deadline, each added three hits for the Giants, who have won three of four at home after losing eight of nine. Pablo Sandoval, in his first start since coming off the disabled list Monday, Angel Pagan and Brandon Crawford also drove in runs. Adam LaRoche drove in a run for the Nationals, who have won 11 of last 14. NL ERA leader Jordan Zimmermann (9-7) saw his six-game winning streak come to an end after allowing two runs on eight hits. He walked two and struck out four. Zimmermann has allowed four or fewer earned runs in all 24 starts this season, including 18 of two or less.Bumgarner lowered his NL-leading home ERA to 1.85 with his second complete game of the season. Pence singled leading off the second and scored when Belt followed with a double. Belt was thrown out trying to stretch it into a triple. Belt also singled home a run in the sixth. The ball hit high off the right field wall but a strong throw from Jayson Werth nailed him at second. The Giants added four runs in the eight on RBIs from Sandoval, Belt, Crawford and Pagan. Werth tripled and scored on LaRoche's single in the seventh for the Nationals. NOTES: Giants RHP Brad Penny was placed on the DL with a right shoulder impingement. RHP Dan Otero was recalled from Triple-A Fresno. ... RHP Tim Lincecum (6-12, 5.35) pitches for the Giants on Wednesday. He is 1-3 with a 5.36 ERA in seven games against the Nationals. ... Scutaro recorded his sixth game of at least three hits this season. ... Giants RHP Shane Loux (neck strain) pitched an inning, with one strikeout, in his first rehab appearance with Fresno. ... Giants OF Melky Cabrera is five hits shy of 1,000. ... Bumgarner is 16-0 when given five runs or more of support. ... RHP Stephen Strasburg (13-5, 2.90) pitches for the Nationals on Wednesday. He leads the NL with 11.2 strikeouts per nine innings. ... Nationals INF Ian Desmond (left oblique strain) could be activated as early as Friday. ... Washington OF Michael Morse was out of the lineup with a jammed right thumb.