Brian Fuentes stood in the Oakland clubhouse and succinctly summed up why he's been struggling for the past week.
"I'm just probably not making pitches," Fuentes said following the Athletics' 5-4 loss to the San Francisco Giants in 11 innings Sunday. "There wasn't really anything that happened that wasn't my fault."
Fuentes, Oakland's fill-in closer while two-time All-Star Andrew Bailey rehabs from a strained right forearm, hasn't pitched in a save situation in two weeks but has three losses in the last five days.
Two of them came in the series with the Giants, who swept the three-game set with their cross-bay rivals after rallying from two runs down in the eighth.
That left Fuentes (1-6) leading the majors in losses by a reliever.
"Things haven't gone perfectly for him the last few outings, that's for sure," A's manager Bob Geren said. "(Opponents are) getting some hits off him. They're not necessarily pounding him and hitting him hard, but they're getting some runs when they need to."
Emmanuel Burriss singled home the winning run Sunday off Fuentes, scoring speedy Darren Ford from second. Ford just beat right fielder Ryan Sweeney's throw to the plate, sending the Giants running out of the dugout to celebrate their fifth straight victory and seventh walk-off win this season.
"I don't know who else scores in the game except Darren," Giants manager Bruce Bochy said. "Anybody else and it's not even close."
Pinch-hitter Nate Schierholtz hit a tying, two-run homer in the eighth off Grant Balfour over the right-field wall and just short of splashing in McCovey Cove. The rally spoiled another stellar outing by A's starter Gio Gonzalez and sent Oakland tumbling to its fifth straight loss and ninth overall at AT&T Park.
The Giants stifled their neighbors across the bay with solid pitching in the first two games, with ace Tim Lincecum throwing a three-hitter Saturday after Ryan Vogelsong allowed only one unearned run Friday. When Oakland finally found a way to score in the finale, it simply wasn't enough.
It was that kind of weekend for the visitors, who broke out of their scoring slump but still came up short.
"Anytime you lose a close game it's tough, but the guys had a lot of energy," Geren said. "It's one you have to shake off and start over. Hopefully the offense the last half of this game takes that momentum down to Anaheim."
Sergio Romo (2-0) pitched two scoreless innings for the win.
Ford started things for the Giants in the 11th with a one-out, pinch-hit single to right. He stole second on the first pitch, and Oakland intentionally walked Buster Posey before Burriss capped the latest Giants rally.
The script was the same almost from the start.
Freddy Sanchez doubled in the first down the left-field line, and Andres Torres hustled from first to beat the relay throw at the plate to give San Francisco a 1-0 lead.
The Giants had a bit of a scare when Posey took a foul tip from Gonzalez off his mask in the second, bringing Bochy and a team trainer out of the dugout to check on the catcher. Posey was holding the right side of his face and ear while grimacing, but he stayed behind the plate.
Posey extended his hitting streak to 11 games with a two-out single in the third. He scored two batters later when Cody Ross grounded to third baseman Andy LaRoche, whose high throw pulled Daric Barton off first base and put San Francisco ahead 2-0.
The offensively challenged A's were held silent until Josh Willingham sparked the team with a solo shot to left off Jonathan Sanchez in the sixth, his seventh home run of the season. Sanchez left after six innings, allowing five hits and striking out five.
Coco Crisp had an RBI double and Barton followed with a run-scoring single against Jeremy Affeldt in the seventh, giving Oakland a 3-2 lead. Pinch-hitter Hideki Matsui drove in Mark Ellis with a sacrifice fly off Ramon Ramirez in the eighth to make it 4-2.
That appeared to be enough behind Oakland's strong pitching staff. Gonzalez left after 6 2-3 innings, striking out eight and allowing two runs on eight hits.
Of course, nothing came easy for the A's in San Francisco.
After Miguel Tejada started the bottom of the eighth with a single, Schierholtz homered on a full count with one out to tie the game at 4, setting the stage for the latest Giants comeback.
"It's a game of little breaks and taking advantage of things," Geren said. "They got a game-changing hit and that was the difference."
NOTES: Bailey (strained right forearm) is slated to make his second rehab appearance with Triple-A Sacramento on Monday. ... LHP Josh Outman will be called up from Triple-A Sacramento to start for Oakland on Monday at the Los Angeles Angels, Geren said. Oakland still has to decide who will start Tuesday with regulars Brandon McCarthy (stress reaction in right shoulder) and Tyson Ross (strained left side) on the disabled list.