OAKLAND, Calif. — Even by Matt Cain's standards, this was a tough one to swallow.

Cain, who has crammed a career's worth of hard-luck losses into his six seasons in San Francisco, went the distance Saturday at the Oakland Coliseum but received little help as the Giants fell to the A's 1-0.

The loss dropped Cain to 2-4 on the season despite a 2.88 ERA. He allowed the leadoff hitter to reach base five times but induced two double plays and struck out four to limit the damage to one unearned run.

"He pitched his heart out," Giants manager Bruce Bochy said. "He had to pitch out of (jams), and he did it. That's why this is another tough one, and we've had some gut-wrenching losses."

The past two have been particularly painful for a Giants club that has dropped four straight and is 1-5 on a seven-game trip.

After leaving seven runners on base in a 6-1 loss Friday night, the Giants stranded five Saturday. San Francisco is 0 for 12 with runners in scoring position in the series and sits dead last in the National League with a .234 average with RISP.

"They're pressing, there's no getting around it," Bochy said. "We're in a tough rut. We're getting shut down, and we know it."

The Giants were baffled by Gio Gonzalez (5-3), who retired the final 20 batters he faced. Gonzalez didn't allow a baserunner in his final six innings, outdueling Cain, who scattered five hits and a walk in eight innings. It was the third time this season that Cain has allowed two or fewer runs and ended up with a loss.

"It's very embarrassing for me, when we have this kind of pitching, to waste a day," catcher Bengie Molina said.

Bochy talked before the game about the need to "do the little things," but it was the A's who were able to put that strategy to use for the game's only run.

Cain had great command throughout, but he plunked Adam Rosales when an inside pitch got away from him at the start of the third inning. Cliff Pennington followed with a slow roller to first, but the potential double-play ball was muffed by Aubrey Huff for an error.

After Rajai Davis bunted the runners over, Rosales scored on Coco Crisp's sacrifice fly to left.

"It came down to one situation, and it worked out in (Oakland's) favor," Cain said. "It was definitely a tough loss."

Cain ended the threat by striking out Daric Barton and later struck out Jack Cust with a runner in scoring position. The A's also hit into double plays in the second and seventh innings to erase leadoff hits.

"Matt knows when to strike a guy out and when to let them put the ball in play," Molina said. "He mixed the ball around and hit his spots well, but he can't hit for us. We've just got to do it ourselves."

The Giants finally threatened in the ninth, when Gonzalez was replaced by closer Andrew Bailey. Edgar Renteria reached on a one-out infield single before Freddy Sanchez struck out swinging on three pitches. With Pablo Sandoval batting, Renteria stole second. After falling behind 0-2, Sandoval fouled off four 96 mph fastballs before drawing a walk on the 10th pitch of the at-bat.

Molina then struck out to end the game.

"Every year you're going to hit a skid like this, it's just how you deal with it that's the most important thing," Molina said. "It usually takes a couple of guys to start swinging the bat, and the rest will follow."