BALTIMORE -- On a night when the Orioles got a strong outing from right-hander Kevin Gausman, the offense failed to support him.
The Orioles haven't scored a run in their last 17 innings, as their September struggles continued with an 11-inning 1-0 loss to the Boston Red Sox before 21,449 at Oriole Park Sept. 19.
Gausman threw eight scoreless innings, allowing three singles. It was Gausman's second-longest start of the season.
While Gausman was good, so was Boston right-hander Drew Pomeranz, who threw 6.1 shutout innings.
"It's a lot of fun. I've had a good amount of those in my career and it's been fun," Gausman said. "Those are games that are really fun. You kind of have a competition between each other -- who's going to crack first. Neither of us did."
The Orioles were hitless in the final 5.1 innings. Their record dropped to 73-79, and they are six games below .500 for the first time since July 28.
"When you get the combination of not operating on all cylinders offensively and really, really good pitching, those things can happen," manager Buck Showalter said. "But kept hoping we'd scratch one across."
The closest the Orioles came to scoring was in the third inning when third baseman Manny Machado doubled with two outs and tried to score on second baseman Jonathan Schoop's single to left. Machado was tagged out at the plate to end the third.
Leading off the fifth, first baseman Chris Davis hit a long drive to center field that Jackie Bradley Jr. caught, possibly robbing the Davis of a home run.
"It's a play that speed allows you to make. He gets there in time," Showalter said. "Would it have gone out? I'm not sure. It probably would have."
Right-handed reliever Brad Brach gave up the winning run in the 11th.
The Orioles are on the verge of ending a streak of five consecutive non-losing seasons, a run that sent them to the postseason three times.
Now, even playing .500 is looking difficult. They must win eight of their final 10 games to break even. They're 5-13 in September.
"It's basically the story of our 2017 season," catcher Caleb Joseph said. "We get an unbelievable pitching performance. We have two chances to score, and you never know, maybe one [run] would have done it."
This month, the Orioles have scored 55 runs, an average of just more than three per game.
"We're liable to score 15 tomorrow. It's frustrating," Joseph said. "It starts to take words out of your mouth."
NOTES: This was the third time this season the Orioles played extra-inning games in consecutive games. They're 12-4 in extra innings. … Instructional League play, which was delayed by Hurricane Irma, will begin at Ed Smith Stadium in Sarasota, Fla., Sept. 25. They'll also play at home Sept. 27 and 30 and Oct. 3. The Orioles games will begin Sept. 23 and end Oct. 7. Admission and parking are free. … LHPs Wade Miley (8-13, 5.32) and Chris Sale (16-7, 2.86) are the scheduled starters for Sept. 20.