The Orioles were shut down by Oakland Athletics rookie Dana Eveland and three relievers for eight innings. They tied the game in the ninth on Ramon Hernandez's RBI groundout, but then lost it in the 10th as Emil Brown hit an RBI single off Jim Johnson, giving the A's a 2-1 victory before an announced 10,128 at McAfee Coliseum.
Johnson, who hadn't given up a run in 16 1/3 innings entering the game, allowed a two-out single to Daric Barton and then walked Frank Thomas before Brown hit a hard liner toward center.
The Orioles, who didn't reward a strong outing by Garrett Olson, have lost five of their past six games. They are at the .500 mark for the first time since their second game of the season.
It was the fourth time in the past six games that the Orioles (16-16) were held to two earned runs or fewer.
Before the ninth inning, the only run was scored on Rajai Davis' infield single off Jamie Walker with the bases loaded in the seventh inning.
Eveland allowed only three hits in seven innings, and Andrew Brown and Alan Embree combined to get the A's out of an eighth-inning jam. With men on second and third and one out, Embree got Brian Roberts to fly out to shallow right field, keeping Adam Jones at third. Nick Markakis then grounded out to end the threat.
However, the Orioles finally got on the board in the ninth against closer Huston Street. Melvin Mora led off with a double, and Aubrey Huff walked. Mora took third on Kevin Millar's flyout. Hernandez followed with a slow roller that appeared to be a potential double-play ball, but A's shortstop Bobby Crosby hesitated on the play before finally taking the out at first base and allowing Mora to score.
In his second start this season, Olson struck out seven, a season high for an Orioles pitcher, and allowed one run on four hits and a walk in 6 1/3 innings. He hadn't walked a batter and had allowed only three hits heading into the seventh. But after he retired Thomas for the inning's first out, he fell behind Emil Brown and allowed a single and then walked Jack Cust on a 3-2 pitch.
With men on first and second and one out, Orioles manager Dave Trembley brought on Matt Albers, who retired Crosby on a flyout. Trembley then inserted Walker to face pinch hitter Jack Hannahan. Hannahan hit a slow grounder to the left side and beat Mora's throw to load the bases.
Davis then hit a slow grounder between first and second. Rather than allowing Roberts to field it at second, Millar ranged to his right to field the ball. However, Davis beat Walker to first base and Millar had nobody to throw to, giving Oakland a 1-0 lead.