Then, for 11 innings at Network Associates Coliseum, they found themselves locked in another pitchers' duel.
The Orioles had the potential go-ahead run on third base with one out in the 12th inning, but the A's threw Luis Matos out at home plate and won, 2-1, in the bottom of the inning on Scott Hatteberg's run-scoring single up the middle.
Once again, the Orioles had to settle for a moral victory after a hard-fought battle with a playoff contender ended in a disappointing loss. In four games at Oakland, including losses of 2-0, 5-3 and 1-0 right before the All-Star break, they had scored four runs.
Yet all of those games were decided after the sixth inning.
"Oakland's got a good ballclub," Orioles manager Mike Hargrove said. "And the gratifying part of it is that the Yankees and Boston and all these guys that are contenders, they're having to play hard to beat us.
"The downside is that they beat us. That's not gratifying at all."
Orioles starter Jason Johnson allowed just one run in seven innings, and he might have had his career-high 11th victory had he not allowed a bases-empty home run to Mark Ellis with two outs in the seventh inning.
The Orioles had taken a 1-0 lead in the fifth inning against A's rookie Rich Harden, when Brook Fordyce hit a leadoff double and scored on a ground ball by Jeff Conine.
Harden left after the fifth, and Oakland's bullpen held the Orioles scoreless for the final seven innings and hitless for the final five.
Mike Wood (2-0) earned the win, and John Parrish (0-1) took the loss.
The game took a twist in the 12th, when Matos took a fastball from Wood off the left wrist. After laying on the ground in pain for several moments, Matos stayed in the game and advanced to third base on an errant pickoff throw by Wood.
Wood walked B.J. Surhoff intentionally, putting runners at the corners, and then Conine hit a bouncer to the first-base side of the pitcher's mound. With Matos racing home, Wood made an awkward toss to catcher Ramon Hernandez, who grabbed the ball on the first-base side of home-plate and spun toward the backstop in time to tag Matos' foot, as he slid in from third.
At that point, Matos left the game and was later taken for X-rays at a local hospital. Hargrove replaced Matos in center with rookie Tim Raines Jr., who was tested immediately when Terrence Long hit a ball into the left-center field gap.
Raines retrieved the ball at the wall, and his throw back to the infield strayed wide of shortstop Deivi Cruz, rolling into foul territory and allowing Long to reach third.
Parrish walked Ellis and former Oriole Chris Singleton intentionally to load the bases, and with right-handed hitting Eric Byrnes due up, Hargrove summoned Hector Carrasco.
"We just felt like Hector's got the nice sinker, and he can get a ground ball," Hargrove said.
Hargrove also went with a five-man infield, bringing Jay Gibbons in to play first base. But Hatteberg, who had missed the previous three games with a strained back muscle, came up and hit a 2-1 pitch up the middle. Cruz dived for the ball but couldn't get it.