DETROIT -- Sean Casey hopes with the start of a new month, his fortunes have changed at the plate.
Craig Monroe also homered for Detroit and Placido Polanco went 4-for-5 with two RBI.
Casey has gotten off to a poor start, hitting only .203. The RBI was only his second of the season.
"I kind of struggled through the first month of April," Casey said. "And, hopefully, it's a good sign for me in May."
Pinch-hitter Carlos Guillen led off the eighth with a walk by Danys Baez (0-1) and was sacrificed to second by Brandon Inge. Curtis Granderson was then walked intentionally. Casey then pinch hit for Neifi Perez and hit a sinking liner that just eluded third baseman Melvin Mora that scored Guillen with the go-ahead run to make it 4-3. Polanco added a run-scoring single.
Casey is also just getting over the flu.
"Just what the doctor ordered, believe me," he said.
Reliever Joel Zumaya (1-1) pitched two innings for the victory. He struck out four and allowed one hit.
He has also struggled recently, but this was his second consecutive effective appearance.
"Just a matter of trying to regain my confidence," he said.
Todd Jones pitched the ninth for his ninth save in 11 chances.
Tigers starter Chad Durbin only lasted 3 2/3 innings. He allowed two runs and three hits, but walked six.
"This was a lucky game for us," said Tigers' manager Jim Leyland. "To walk that many guys."
Orioles' starter Adam Loewen gave up three runs and seven hits in five innings.
"He pitched good. He was aggressive and tried to hit his spots," said Baltimore catcher Ramon Hernandez. "He made one mistake to Monroe but threw pretty well."
The Orioles tied the game 3-3 in the seventh on Miguel Tejada's one-out RBI single off Zumaya.
Baltimore took a 2-0 lead in the third inning on Mora's fourth homer of the season to lead off the inning. Hernandez added an RBI groundout.
The Orioles had a total of nine baserunners in the first four innings, but could only manage the two runs.
"We had chances early to put it away but couldn't, we then had to battle all night," said Baltimore manager Sam Perlozzo. "We need someone to come through with the big hits to extend the lead. We just haven't been able to do that."
Detroit went ahead 3-2 in the fifth. Polanco singled in Ivan Rodriguez, who led off with a double. With two outs, Monroe connected on Loewen's 1-0 pitch for his second home run of the season, which landed in the left-field stands.
Brian Roberts scored on a ground out by Tejada in the ninth to make it 5-4.
Guillen didn't start at short for Detroit because of a sore right shoulder. Tigers' manager Jim Leyland said Guillen would also be rested Wednesday afternoon. He's been bothered by it for most of the season. ... Tejada was booed most of the game after he helped touch off an incident which cleared both benches and bullpens on Monday night when he pointed his bat and started yelling at Tigers' pitcher Jeremy Bonderman after he had to skip out of the way of one of Bonderman's pitches. ... Detroit's Magglio Ordonez was 1-for-4 and has hit safely in 11-of-his-last 12 games (21-for-43). ... Roberts stole three bases in three attempts to make him 11-of-12 for the season.