OAKLAND, Calif. -- Maybe it's the sparse crowd. Maybe it's the cool Bay Area weather. Or maybe there's something about the spacious confines at the Coliseum.
Joel Pineiro's struggles in Oakland simply have him stumped.
"It's just the curse of the elephant I guess," Pineiro said, referring to Oakland's mascot, Stomper.
Willingham's three-run shot in the first inning off Pineiro (6-7) started a second straight brief outing for the Angels right-hander at the Coliseum. Los Angeles fell three games behind first-place Texas in the AL West.
Pineiro allowed four runs on five hits in three-plus innings. His short start still lasted longer than his previous performance in Oakland on July 17, when he gave up eight runs in one-third of an inning.
"It was deja vu," he said.
Gio Gonzalez (13-12) struck out six and gave up two runs in 6 2/3 innings.
Erick Aybar and Vernon Wells each hit solo home runs late for the Angels, who had won six of their last eight games to climb back into the playoff race. With only 15 games remaining, time is running out to catch the Rangers.
"All is not lost," Angels right fielder Torii Hunter said. "We can still win the series, and that's all you can ask for."
Angels manager Mike Scioscia had hoped that Pineiro's struggles were over. He had a six-start winless streak until his last outing -- allowing one run in seven innings in a 4-1 victory over Minnesota -- and seemingly fixed the mechanics in his release point that were at the root of his problems.
All that washed away quickly.
Pineiro walked two of the first three batters and pitching coach Mike Butcher visited the mound for a chat before Willingham came to the plate. Willingham sent a 1-1 pitch soaring into left-center field, skipping off the top of the wall for a home run to put the A's ahead 3-0 in the first inning.
"We signed up for 162 of them. You have to play them all," Willingham said. "In Texas, we were aware we were going to have an impact on the playoffs, whether it was good or bad. It's the same with these guys."
After Hunter singled leading off the second, Wells hit a line drive that ricocheted off the wall just below the foul pole in right. The ball skipped back over the outstretched arms of David DeJesus, giving Wells a triple and allowing Hunter to score to bring the Angels within 3-1.
Ryan Sweeney singled and Kurt Suzuki hit one his two doubles to start the bottom of the fourth. That was enough for Scioscia to pull Pineiro for Tyler Chatwood after a start that was reminiscent of Pineiro's last visit to Oakland, a 9-1 loss that was the shortest appearance by an Angels starter -- not counting an injury or ejection -- since Aug. 28, 2007.
The A's kept piling it on with a rare display of pop.
Scott Sizemore hit a run-scoring single and Cliff Pennington knocked a two-out RBI single later in the inning to put Oakland ahead 5-1. After Aybar hit his 8th home run of the season in the seventh, Willingham answered with an RBI single in the bottom of the inning to give the A's a 6-2 lead.
Wells homered for the 21st time this season in the ninth off Grant Balfour. Oakland has won 10 of the last 12 home games against the Angels.
"I don't know if it's a freak season," Scioscia said, "but we've been outplayed by that team this season."
The A's held out closer Andrew Bailey as a precaution after he was hit just above his left ear by a foul ball from teammate Suzuki during batting practice. He passed an initial concussion test. Bailey said his vision momentarily went black but joked that his sunglasses saved him and he'll be fine. ... Scioscia said ace Jered Weaver, who is scheduled to start Wednesday in Oakland, could pitch on three days' rest Sunday at Baltimore. That would allow the right-hander to get an extra start in the season finale at Texas on normal rest. ... Oakland CF Coco Crisp was scheduled to have a precautionary MRI exam on his right foot, which he injured taking two foul balls off of it last week. Manager Bob Melvin said he was hopeful Crisp could return this season. ... The Angels will send RHP Jerome Williams (3-0, 3.51 ERA) to the mound Tuesday against A's RHP Guillermo Moscoso, who didn't allow a hit until the eighth inning in his last start against Kansas City.