Chris Leroux allowed eight runs while only getting one out in his start on Sunday, and the Pirates lost 12-10.
The Pirates tied the game at 10 with a five-run sixth, but the Orioles scored the go-ahead run in the next half-inning.
Andrew McCutchen went 2-for-3 with a homer, a double and a walk, and Gaby Sanchez went 3-for-4 with a double. Lucas May also had three hits. The Bucs had 17 hits in total.
Russell Martin was ejected during Leroux's blowup in the first.
After Leroux's implosion, Justin Wilson allowed one run in 2.2 innings. Jared Hughes then pitched a scoreless inning, followed by Ryan Reid, who allowed one run in the fifth. Mike Zagurski and David Bromberg handled the last four innings, allowing one run each.