At a time when he's usually sleeping or eating breakfast back home in San Francisco, Madison Bumgarner was on the mound facing the Washington Nationals.

Maybe it was the early starting time, or the way the ball carried on a steamy day in the nation's capital that led to his uncharacteristically poor performance. Or maybe the left-hander was just due for a clunker.

Bumgarner allowed a career high-tying three home runs and a season-worst seven runs over five-plus innings in the Giants' 9-4 loss Wednesday.

Coming off a one-hit shutout against Cincinnati and riding a five-game winning streak, Bumgarner (10-5) yielded more runs than in his previous four starts combined, and the three homers were one more than the total he gave up in his last seven outings.

"He's been so good," manager Bruce Bochy said. "That's a good hitting club and they took advantage of his mistakes today. It's going to happen."

Bumgarner hadn't been knocked out of a game this early since his first start of the season. Clearly, something was off.

"Guys have days like this all the time," the pitcher said. "It just depends on how good you can minimize the damage. I didn't really minimize it today."

Both teams benefited from a breeze that seemingly turned long fly balls into home runs.

"It looked like the ball was carrying today," Bumgarner said, "but they put the good part of the bat on it."

Bumgarner and the Giants were operating on West Coast time, so the 11:08 a.m. start was actually 8:08 on the West Coast. If the players appeared to be sleepwalking during the game, it was completely understandable.

"You travel across the country and get acclimated to the time change, then have to bounce back to play an early game like this," Bochy said. "Sure it played a part. But it's part of the schedule and you deal with it."

San Francisco scored three runs in the first inning before tailing off dramatically. The collapse became complete when Rick Ankiel hit a two-run homer off Clay Hensley in the eighth to make it 9-4.

Pablo Sandoval had three hits, including a homer, and drove in two runs for the Giants. San Francisco has lost four of five overall and seven of their last 10 on the road.

"We have a better sense of comfort at home," Bochy said. "That goes without saying."

Ryan Zimmerman, Michael Morse and Jhonathan Solano homered for the Nationals, and Edwin Jackson (5-4) allowed four runs and five hits in 5 1-3 innings. Three relievers combined to shut down the Giants the rest of the way.

Washington has scored 18 runs in the first two games of the series and will go for the sweep Thursday. The Giants have allowed at least nine runs in consecutive games for the first time since 2009.

"They're playing well. They're clicking offensively," Bochy said of the Nationals. "We knew that coming in."

"Another fun day for the skipper," Washington manager Davey Johnson said. "You've got to tip your cap to our offense."

The Giants took a 3-0 lead in the first inning with an uprising that began when Jackson walked leadoff hitter Gregor Blanco. After Melky Cabrera singled and Buster Posey hit a run-scoring groundout, Sandoval drove a 1-2 fastball over the center-field wall.

In the bottom half, Bumgarner hit Danny Espinoza with a pitch, and with one out was struck in the leg by a line drive off the bat of Zimmerman. Bumgarner chased down the ball in time to make the throw to first base.

Bumgarner retired the first two batters in the third before singles by Espinoza and Bryce Harper put runners at the corners for Zimmerman, who hit an RBI double off the top of the left-field wall. His run of 14 straight scoreless innings over, Bumgarner walked Morse to load the bases for Ian Desmond, who tied the game with a two-run single.

Solano put the Nationals up 4-3 in the fourth with his second homer in nine major league games, a soaring liner to center that carried into the seats.

In the fifth, Harper singled and Zimmerman followed with an opposite-field drive to right. Morse then homered on an 0-2 pitch for a 7-3 lead.

Sandoval doubled in a run in the sixth.

NOTES: The Nationals returned C Sandy Leon from rehab, reinstated him from the 15-day disabled list and optioned him to Double-A Harrisburg. ... Matt Cain starts for the Giants in Thursday's series finale, facing Ross Detwiler of the Nationals. ... SF went 1 for 5 with runners in scoring position and is 2 for 21 in that situation in the series.