They won it on a bloop.
Major league homer leader Chris Davis dropped a bloop single into short left field in the last of the 13th and it scored Nick Markakis and the O's outlasted Boston 5-4 with a walkoff win in the 13th.
With two outs against Alex Wilson, Markakis walked and Adam Jones singled to right. That set the stage for the walkoff blooper by Davis and the O's victory.
Tommy Hunter kept this game tied at 4-4 and gave the O's some momentum on the mound tonight. He pitched 2 1/3 scoreless innings on 21 pitches, with 18 for strikes. He retired every batter he faced and fanned two in the top of the ninth.
For the second day in a row, a 4-2 O's lead was lost in the top of the seventh. This time they didn't fall behind, but were tied 4-4 as Boston rallied vs. Brian Matusz on RBIs by Stephen Drew and Jacoby Ellsbury.
The lost lead cost Kevin Gausman a shot at his first major league win. Gausman, who gave up seven runs in his last start, tonight went 5 1/3 innings, allowing six hits and two runs (both earned) with no walks and five strikeouts. He threw 91 pitches, 56 for strikes and lowered his ERA to 7.66.
The Orioles went ahead 3-0 in the last of the third. Danny Valencia led off the inning with a solo homer off Boston starter Felix Doubront. Later, Manny Machado and Davis added RBI singles.
Boston pulled within 3-2 on homers by David Ortiz and Mike Carp back-to-back in the fourth off Gausmnan.
The O's lead grew to 4-2 in the fifth. Markakis reached on an error and later scored on a Matt Wieters' RBI single.