SAN FRANCISCO (AP) — Matt Cain's promising return from a stint on the disabled list with a strained right hamstring was short-lived. His second start back was even shorter.
Cain walked the first three batters he faced during a three-run first inning to set the San Francisco Giants up for a third straight loss to the Washington Nationals, 6-2 Friday night.
"It was too much of a deficit to come back from," Cain said. "We needed a better start than that. I wanted some clean innings. I made it too difficult."
Cain, who tossed seven innings of two-run ball in San Francisco's 4-2 win against the New York Mets on Friday night, reverted to his early season woes against Washington. The former ace allowed four runs and three hits in five innings, walking five and striking out four.
Adam LaRoche followed the opening walks with a two-run single off Cain (1-4) in the first. Jayson Werth's solo shot in the fifth and two-run single in the ninth provided the rest of the pop for the Nationals, who have won 10 of 12, including the last three at San Francisco.
"I've never seen that from Matt," Nationals manager Matt Williams said. "I've stood in that coaching box over there a lot, 99.9 percent of the time he's pinpoint with his control. But it's nice, the guys were patient, didn't expand their strike zone and we were able to get him early."
Brandon Crawford and Pablo Sandoval each drove in a run for the Giants, who tied a season high by losing three straight after winning five in a row.
The finale of the four-game series is Thursday, but the NL East-leading Nationals already have handed San Francisco its first series loss since the Giants were swept at Pittsburgh from May 5-7. The Giants had not lost two in a row since May 16-17 to the Marlins until the Nationals showed up in San Francisco this week.
"We're going through a rough spot," Giants manager Bruce Bochy said. "What's important is how we deal with it."
Even with standouts Bryce Harper and Gio Gonzalez on the disabled list, the Nationals are surging up the standings by getting contributions at the plate, on the mound and in the field.
Nationals starter Tanner Roark (5-4) allowed two runs and seven hits in six-plus innings, Werth homered for the first time in almost month and Washington's defense did the rest.
After Crawford's RBI triple in the fourth, second baseman Danny Espinosa made a diving stop on Gregor Blanco's sharp grounder and threw out the speedy runner at first. Former third baseman Ryan Zimmerman, filling in for Harper in left, also swiped another run from San Francisco in the sixth when he made a diving catch of Crawford's slicing fly after Michael Morse doubled.
"I'm kind of learning on the fly," Zimmerman said. "Got a good break on it. It kept tailing away. I dove and caught it. The landing wasn't very smooth, but in the end, I caught the ball."
Sandoval, scratched from the starting lineup because of an illness, singled home a run as a pinch-hitter in the seventh to whittle Washington's lead to 4-2. Zimmerman slid in to snag Angel Pagan's short fly for the third out.
With his back right leg almost touching the dirt, Werth went low to launch his sixth homer of the season to put the Nationals up 4-1 in the fifth. Werth, who had not homered since May 14 at Arizona, singled with two outs in the ninth off Yusmeiro Petit to extend Washington's lead to 6-2.
Drew Storen, Tyler Clippard and Jerry Blevins each tossed a scoreless inning to help Washington finish off San Francisco again.
NOTES: The Giants traded left-hander David Huff back to the Yankees for cash. He was sent to San Francisco in January for cash after the Yankees signed Masahiro Tanaka. ... Tim Hudson (6-2, 1.97 ERA) takes the mound for the Giants opposite Washington's Blake Treinen (0-2, 1.78 ERA) in Thursday's series finale.