WASHINGTON -- Bryce Harper homered, Tyler Mooredrove in four runs and the Washington Nationals defeated the San Francisco Giants 9-3 on Saturday despite Stephen Strasburg exiting in the fourth inning with an apparent injury.
Strasburg allowed one hit over 3 2/3 scoreless innings in his third start since coming off the disabled list. He missed nearly four weeks due to neck tightness.
Strasburg winced and grabbed in the area of his left side after making an attempt at Buster Posey's groundball out. He walked off the mound and into the dugout following a lengthy conversation with Nationals manager Matt Williams and a team trainer.
Harper and Moore each had three hits.
Rain delayed the game's scheduled first pitch by 19 minutes. Washington's offense got to Madison Bumgarner (8-5) quickly with four consecutive hits including home runs by Michael A. Taylor and Harper.
Bumgarner surrendered a season-high six runs and eight hits in five innings plus two batters. The defending World Series champion Giants have lost five straight.
Tanner Roark (4-3) earned the win after pitching 4 1/3 innings in relief of Strasburg.
Taylor drilled the first pitch of the game from Bumgarner just over the left field wall. The second pitch barely stayed in the park. Yunel Escobar's fly ball smacked off the wall in center for a double.
Washington went up 3-0 three pitches later. The lefty-swinging Harper turned on a fastball for his 25th home run of the year. Harper also doubled in the seventh.
Bumgarner allowed a single to Wilson Ramos before recording his first out. The 2014 World Series MVP had not allowed more than two runs in any of his previous four starts, but went 1-2 in that stretch.
Moore's RBI double off Bumgarner in the fourth scored Washington's fourth run. His second two-base hit drove in two in the sixth. Moore added an RBI single during a three-run seventh.
Roark allowed five hits and two runs for the NL East-leading Nationals, who improved to 45-36 exactly halfway through the season.
Including Friday's 2-1 victory, the Nationals opened the series with consecutive wins after losing two straight in Atlanta.
Giants: OF Angel Pagan was out of the starting lineup for the second time in three games. The 34-year-old was reportedly dealing with a swollen left knee during the previous series against Miami.
Nationals: Strasburg went 2-0 with a 1.50 ERA and 15 strikeouts in his previous two starts since returning.
Giants: RHP Ryan Vogelsong (6-6, 4.19) went 2-4 with a 4.11 ERA over six starts in June.
Nationals: RHP Jordan Zimmermann (6-5, 3.16) faces the Giants for the first time since allowing one run over 8 2/3 innings in Game 2 of their NLDS matchup last year. Washington lost 2-1 in 18 innings.