The comeback was also the biggest ever by a last-place team over a first-place team.
The franchise's largest comeback prior to this was an eight-run jaunt in 1956, also against Boston. And though lots has transpired between the two teams over the past five decades, one thing hasn't changed: The Orioles still regard any victory over the Red Sox as a blessing, especially one in which the Red Sox had pushed ahead early.
"That was probably the best game I've been involved in. ... That was absolutely tremendous," said manager Dave Trembley. "It's got to mean the world to these guys, and rightfully so. They're a very good team, and they threw their best out there, one right after another. It was the shootout at the OK Corral, but it was at Camden Yards."
A win seemed unlikely enough at one point that the Orioles began resting their starters -- specifically, Melvin Mora in the seventh inning. Baltimore trailed by nine runs when that inning began, and three hits later it was an eight-run game. Pinch-hitter Oscar Salazar made it even closer with a three-run homer off Justin Masterson.
The Orioles trailed by four runs when the seventh ended and began their charge anew in the eighth. The first three hitters reached on hits off Hideki Okajima before Matt Wieters singled home Nolan Reimold to cut the lead to 10-7. Ty Wigginton then brought Baltimore within two on a sacrifice fly. That brought to the plate Brian Roberts, who was in the middle of an 0-for-18 slump.
Roberts broke that skid -- and consigned it to ancient history -- with a single up the third-base line, chasing one run home and pushing the potential tying run to second base. Boston turned to closer Jonathan Papelbon at that point, and after Felix Pie struck out, Nick Markakis doubled to left-center to put Baltimore ahead.
"I think you could certainly feel the momentum was going our way," said Roberts, "but we still had some work to do. Guys just really had good at-bats, and even if people didn't get hits, they did what they needed to do. Wiggy had a real nice piece of hitting just to get a run in and keep guys moving along the bases."
"That's why we play nine innings," added Markakis, who finished the game 2-for-5. "We were down early, and all game. The pitchers kept us in the game there, and we swung the bats well as a team."
Starter Rich Hill, the main story early in the game, slowly became an afterthought. The southpaw allowed nine hits and seven earned runs and was removed before completing five innings for the fourth time in his past five starts. He has a 10.42 ERA over that span and has given up 27 hits and 15 walks in his past 19 innings.
The game turned a bit in the bottom of the fifth, though, after rain caused a 71-minute delay. The Orioles didn't respond immediately, but they did slowly begin to stir. Still, a comeback appeared out of the question, as Boston had won 11 of the past 12 games against Baltimore, with many of those victories one-sided.
Baltimore rendered that history moot with its resilient comeback, an effort that mostly tagged two Boston relievers. Masterson was charged with five earned runs, and Okajima allowed four more. Takashi Saito (2-1) took the loss, and Papelbon was tagged with just his second blown save of the season.
For Baltimore, a team that was 0-for-34 when trailing after eight innings just two weeks ago, the win could mean something profound. The Orioles have now come back to win three times in their past 12 games.
"When we were 0-and-34 late going into that win against the Mets, I [said], 'I think one time you do it, you can do it again,' " said Trembley of his team's resiliency. "You start to believe, especially here at home. You have a lot of pride playing here at home. A lot of pride. That was fun. Gosh darn it, that was fun."
It wasn't as much fun for the Red Sox (47-30), especially when you consider their perspective. Kevin Youkilis gave them a two-run lead in the first inning with a home run, and Boston scored twice more in the fourth. The Red Sox took control with five more runs in the fourth, only to wilt after the rains came.
"I think it shows we can score with anybody and we can score off anybody," said Roberts, who has the second-longest tenure on the team. "But we need to do it a little earlier and more often, probably."
Of course, the game wasn't over until George Sherrill worked the ninth. The southpaw allowed a single to the first batter he faced, then calmly worked over the top of Boston's batting order. Sherrill retired Julio Lugo and Dustin Pedroia before hitting Youkilis, and with the tying run on second, he struck out Jason Bay.
That sent the Orioles into instant celebration mode and gave Sherrill his 17th save of the season.
"One-run saves are tough," said Sherrill. "I haven't been part of a winning team yet, so I guess when we get to 83 wins, that will be more exciting. Until then, this is probably one of the biggest."
Spencer Fordin is a reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.