Starting pitcher Dan Haren struggled in his second-shortest outing of the season, the offense was silent until the ninth inning, and the Angels also made a costly error in an 8-3 defeat Friday night.
Los Angeles remained 3½ games behind first-place Texas in the AL West and dropped five games behind Boston in the wild-card race.
"A lot of things they did on the field better than we did," manager Mike Scioscia said. "We have to play at a higher level."
After the Angels fell behind 8-0, Scioscia pulled every one of his position players except third baseman Alberto Callaspo.
"No message," the manager said. "At this part of the season, in a game like that, we needed to get some young legs out there and let these guys regroup."
Tommy Hunter (4-4) pitched seven shutout innings for the Orioles, who have become spoilers of late. Baltimore took two of three from wild-card hopeful Tampa Bay before easily handling the Angels, who had won eight of 11 coming in.
"We'd like to finish strong no matter who it is out there," Hunter said. "It's not one of those things where we're going to play harder against one of these teams or that team. This team is young. We want to go out there and play, no matter who it is."
"We lost. It's very concerning," outfielder Torii Hunter said. "We didn't play like a team that is in the pennant race."
Tommy Hunter gave up seven hits, struck out five and walked two in his most impressive outing since coming to Baltimore on July 30 from Texas. He came in 1-4 with an 8.79 ERA in seven career games against Los Angeles.
Haren (15-9) yielded seven runs and seven hits in five-plus innings.
"Everyone knows that every game is important. I feel terrible," the right-hander said. "We have some games to make up and time is running out."
Haren got into trouble in the second, when the Orioles manufactured two runs on one hit. Reimold walked, stole second and scored on Robert Andino's single. A sacrifice bunt and a wild pitch got Andino to third, and he came home on J.J. Hardy's groundout.
Baltimore made it 5-0 in the fifth. After Reynolds led off with his 33rd homer and Andino got an infield hit, Callaspo let a grounder go through his legs for an error. Hardy followed with a two-run double.
Any hope the Angels had of a comeback ended in the sixth, when the Orioles increased the lead to 8-0. Chris Davis led off with a single and Reynolds doubled to chase Haren. Tyler Chatwood entered and threw a wild pitch, allowing Davis to score, and Reimold followed with a drive to left on an 0-2 pitch.
Orioles CF Adam Jones was a late scratch with a sore thumb. He has missed six straight starts, and manager Buck Showalter said Jones will get an MRI on Saturday. Jones' absence provided Reimold a chance to play. ... Reynolds' homer ended an 0-for-21 skid. ... Los Angeles was averaging 6.8 runs per game against the Orioles. ... RHP Ervin Santana (11-11) will start for the Angels on Saturday against rookie Zach Britton (9-10). Santana has won five straight road starts but has a 6.75 ERA at Camden Yards.