WASHINGTON — Madison Bumgarner barely broke a sweat before the Nationals got to him.
The San Francisco Giants ace struggled again in a late-morning start, allowing a season-high six runs over five-plus innings in a 9-3 loss to the Washington Nationals. Three of those runs came before Bumgarner had retired a batter.
"He just got ambushed," said Giants manager Bruce Bochy. "They came out swinging."
Brandon Crawford, Gregor Blanco and Brandon Belt had RBIs for San Francisco, which lost its fifth straight game.
The Giants entered the day three games behind NL West-leading Los Angeles Dodgers.
"We feel pretty good about our club," said Bumgarner, who allowed eight hits in his shortest outing since May 9. "There's been a lot of really good ups this year and some really bad downs this year at the same time, and we're sitting in a pretty decent spot right now for the time of the year."
Michael A. Taylor and Bryce Harper both homered early for the NL East-leading Nationals, who lost starter Stephen Strasburg to an injury in his left side in the top of the fourth inning.
Tyler Moore had two doubles, three hits and drove in four runs for Washington exactly three years after the Nationals touched up Bumgarner for seven runs in five innings on a steamy Independence Day affair in 2012.
Bumgarner has allowed two earned runs over 17 innings in his three other starts in Washington.
"I don't know if I can pitch him in this game," Bochy said. "His numbers aren't very good in this 11 o'clock game. Last time he pitched here he thought he was trying to conserve his energy with the heat. But he wasn't trying to do that today."
Unlike three seasons ago, rain delayed Saturday's scheduled first pitch by 19 minutes, and when play started temperatures were in the mid 70s.
It didn't matter, as Washington's offense got going quickly with four consecutive hits including home runs by Taylor and Harper.
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.
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, runs charged to Bumgarner after he let the first two batters of the inning reach base.
Tanner Roark (4-3) earned the win after pitching 4 1/3 innings in relief of Strasburg.
"It was just one of those days," Bumgarner said. "I was definitely ready for the early game and for the heat, which it wasn't too hot today. Mentally I was locked in. Can't make any excuses about that."
Giants outfielder Ryan Lollis, 28, went 0 for 4 with a strikeout in his major league debut.
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. Bochy said the knee was still bothering Pagan, but expected him to return Sunday.
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.