OAKLAND -- For months, the Oakland Athletics were among baseball's best offensive teams.
Their baffling, extended hitting slump could cost them a playoff berth if the bats don't turn around in a hurry.
Jerome Williams beat the A's for the third time this season with his third different team, and Oakland missed an opportunity to extend its lead in the AL wild-card race with a 3-0 loss to the Philadelphia Phillies on Saturday.
"We've been struggling for a while, and this is a guy we had really good numbers off of," A's manager Bob Melvin said. "Just the production across the board from everybody was much better in the first four months or and hasn't been since. When you continually struggle, sometimes it affects your confidence but that's not an excuse. We should have confidence based on the amount of runs that we scored earlier in the season."
The A's remained a half-game ahead of Kansas City for the top wild-card spot. The Royals lost 3-2 to Detroit earlier Saturday.
"Right now, we know every pitch matters," Otero said.
Williams (4-2) is the first player since at least 1900 to have at least one win against the same opponent with three different teams in the same season, according to STATS.
"I've been aware of it since I knew I was going to pitch against these guys," Williams said. "That is crazy. For one, you would never think that you would face the same team. Obviously I was with the AL West so I knew I was going to face them, but coming over to the Phillies in interleague play, you didn't think you were going to face the team again. It's a good feat."
He allowed four hits, struck out three and walked one in seven innings. The right-hander was 0-2 with a 4.08 ERA in his previous three starts.
Williams was aided by double plays in the second and fifth innings. He also won against the A's this year with Houston and Texas.
Oakland lost for the seventh time in 10 games, again failing to support its starting pitcher. The A's squandered a bases-loaded chance in the second when Derek Norris grounded into an inning-ending double play.
Drew Pomeranz gave the A's all they hoped for from him in a spot start, allowing one hit and walking two in five scoreless innings. Melvin expected him to throw between 75-80 pitches and he finished at 86.
Pomeranz escaped a bases-loaded jam in the first and retired 10 straight batters from there.
The left-hander made his first start since another spot outing Aug. 27 at Houston. Jason Hammel will return to the rotation Thursday when he rejoins the club from his paternity leave.
Ken Giles became only the second Phillies pitcher to earn a save this season, finishing the four-hitter. Suspended closer Jonathan Papelbon has the other 37.
Philadelphia earned just its third win in eight games at the Coliseum and improved to 2-4 on its final road trip of the year.
Phillies: Oakland native Jimmy Rollins, still recovering from a strained left hamstring that has sidelined him since Sept. 8, expected a few family members in the stands Saturday but the infielder told some there was no pressure to come with him being hurt.
Athletics: CF Coco Crisp had most of the day off until entering as a pinch hitter in the eighth. He had played 14 straight games since missing five with a strained neck. ... RHP Jarrod Parker, who has missed the season following a second Tommy John surgery, will travel to Arizona on Wednesday to continue his throwing program. He hopes to pitch at least twice off the mound this fall before shutting it down in November for the rest of the year. He hopes to be back by next June.
Phillies: RHP A.J. Burnett (8-17, 4.40 ERA) tries to end a two-start losing streak when he makes his first start against the A's since losing with the Yankees on July 23, 2011.
Athletics: LHP Scott Kazmir (14-9, 3.44 ERA) looks to snap an 0-4 skid over his last five starts. He is 14-6 with a 4.31 ERA in 26 interleague starts.
Utilityman Stephen Vogt, who began the season at Triple-A, received the team's Jim "Catfish" Hunter Award from teammates and coaches for an A's player best representing the late Hall of Fame pitcher's "courageous, competitive and inspirational spirit" on the field and in the clubhouse. "It just means the world to me to have an honor like this. It says a lot about what your teammates and everybody thinks about you," said Vogt, who appreciates all those fans who chant, "I believe in Stephen Vogt!"