BALTIMORE -- Derrek Lee had gone nearly seven weeks without hitting a home run -- not nearly long enough to forget the sensation of getting good wood on a pitch and sending it soaring toward the seats.
So when Lee made contact in the 12th inning, he knew his long-ball drought was over.
Lee sent a 1-2 pitch from Jose Arredondo (0-3) into the seats in left field to end the marathon. It was Lee's fifth home run, the first since May 8.
"It felt good to finally get one over the fence," he said. "... I put a good swing on that one. If that one didn't go over the fence, we would have had some problems."
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Lee came into the game with a .238 batting average and had only 18 RBI. He knew he wasn't contributing as much as expected, but on this night he went 3 for 5 and scored twice.
"I'm happy for him. I'm happy for us, too," Orioles manager Buck Showalter said.
It was his third career walkoff homer, the first since May 11, 2005.
"That was a tough one to lose," Reds manager Dusty Baker said. "We got out of trouble quite a few times tonight."
Mike Gonzalez (1-1) worked the 12th for the Orioles, who led 4-0 after four innings. Baltimore stranded 13 and went 2 for 14 with runners in scoring position.
"It was a game that we thought we had in hand. We would hate to see that one get away," Lee said. "We didn't execute great, but we grinded it out and were able to get a win."
Cincinnati is 4-4 with four straight extra-inning defeats.
"Some balls in the outfield dropped in, just out of the reach of the gloves," designated hitter Jonny Gomes said.
Adam Jones homered for Baltimore, and rookie second baseman Blake Davis -- who made a costly error Wednesday in a 5-4 loss to Pittsburgh - rebounded with his first major league hit: a two-run triple that made it 2-0 in the second inning.
"I felt like I was floating around the bases," said Blake, who stuffed the prized baseball in his locker.
A sellout crowd of 45,382 watched Cincinnati's first appearance in Baltimore since the 1970 World Series. During the 15 years that interleague play has been in existence, the Reds faced every AL team on the road except the Orioles.
Reds starter Edinson Volquez gave up four runs, seven hits and five walks in 4 1-3 innings.
Volquez entered with a 13.85 ERA in the first inning, but he kept the Orioles scoreless despite walking two batters.
In the second inning, however, Volquez surrendered the game's first run for the 12th time in 14 starts. Lee walked and took third on a double by Matt Wieters before Davis tripled to right-center.
Jones led off the third with his 12th homer for a 3-0 lead. In the fourth, Wieters doubled and came home on a broken-bat bloop by J.J. Hardy.
- Baltimore's Nick Markakis extended his hitting streak to 14 games.
- Former Oriole Ramon Hernandez went 2 for 4 with a walk.
- Volquez has 84 career starts without a complete game.
- Orioles LHP Brian Matusz seeks his first interleague win Saturday. He's 0-3 in four starts lifetime.
- Lee had his 15th multihit game, the fifth in his last seven starts.
- Reds DHs are 2 for 16 (.125) this season.