Mark Reynolds hit an RBI single in the 11th 4 victory over the streaking Yankees to avoid getting swept.
With Hector Noesi (2-1) on the mound, Matt Angle reached base when shortstop Eduardo Nunez failed to field his ground ball, then stole second. The Yankees intentionally walked Nick Markakis to bring up Reynolds, who slapped a single to center to put the Orioles on top.
"I just went up there and tried to get a pitch over the plate I could handle, stay on top of it," Reynolds said. "I was able to do that because the ball wasn't really traveling today to hit a home run. I just got on top of the slider and hit a line drive to left."
But Robert Andino dove to knock it down, then scrambled to shovel a throw to Ryan Adams. He stepped on second base a moment before Curtis Granderson slid in, ending the game and snapping Baltimore's four-game slide.
Nolan Reimold hit a two-run homer in the victory.
Alex Rodriguez hit a two-run double for the Yankees, who had won six in a row and nine of 10. They still hold a 2 1/2 game lead on Boston in the AL East.
The extra-inning game came on the heels of the teams' late-night contest, which was delayed by four hours because of rain and didn't finish until about 2:15 a.m. (et) Wednesday morning.
"The way our schedule sets up right now isn't exactly the best," Yankees outfielder Nick Swisher said. "Close games, every game is important now. We had to call in all the boys, but it just wasn't our day today."
The extreme circumstances of that contest prompted Yankees president Randy Levine to release a statement Wednesday, saying that the decision to play was a "collaborative effort" between Major League Baseball and the Yankees.
"Every possible effort was made to play the game because there were no suitable alternative dates on which to play a rescheduled game given the poor weather forecast for Wednesday," the statement said.
Rain didn't cause as much of a disturbance Wednesday, though did start to fall in the eighth inning. A greater disturbance was the teams' inability to score after the fourth inning.
Angle began the contest with a single, stole second, then scored on consecutive groundouts.
In the bottom half, Russell Martin doubled and Swisher walked to set up Rodriguez's two-run double deep to center.
The Orioles tied the game in the second thanks in part to Yankees starter A.J. Burnett's lack of control. He walked Reimold, who stole second and took third on a wild pitch. Burnett then walked Ryan Adams before Brandon Laird committed a fielding error on a ball by Kyle Hudson, allowing Reimold to cross the plate.
Reimold's two-run blast in the third put Baltimore ahead, but the Yankees tied the game again in the fourth.
A Rodriguez walk and Andruw Jones double put runners in scoring position for the rookie Montero, who singled to right to make it a 4-4 contest.
But after that, neither team could push a run across. The Yankees put their leadoff batter on base in the ninth and 10th innings, but couldn't score. Pedro Strop (1-1) recorded the final out of the ninth and pitched a scoreless 10th to pick up his first major league victory.
The teams will play a make-up game Thursday in Baltimore...Burnett pitched six innings for the first time since August 9. He allowed four runs on seven hits and four walk, while striking out seven...Orioles starter Zach Britton gave up five hits and two walks along with four runs in five innings...Noesi's loss was the first of his major league career.