BOSTON -- It wasn't exactly a triumphant return for Garrett Olson, who fought through some struggles in the early innings and succumbed to relentless pressure later in Monday's game. It was Labor Day indeed for the left-hander, who came back from a brief layover in Triple-A and got worked for six runs by the Red Sox in a 7-4 loss for the Orioles.

Still, Olson came away from his start undaunted and undeterred, convinced that he'd made some progress since the last time he'd pitched in a big league game. The loss stung, no question, but Olson could point to positives.

"I feel like my fastball command overall and mound presence, my tempo, I think everything is a lot better and I think I'm back on the right track," said Olson, who has lost four of his past six decisions. "I worked on some things when I went down and came back up with some confidence. ... I'm encouraged to get out there and work some more. I'm just trying to get out there, I think, with everyone else. It's been a long year and we're just working real hard right now to finish this season strong."

Olson started out shaky, walking three of the first five batters he faced to load the bases. And he worked his way out of that jam, striking out Jed Lowrie to escape the first inning with a one-run lead. Olson gave that right back on back-to-back home runs in the second inning, but he rebounded to retire 12 of the next 13 batters he faced.

"Hopefully, he pitches like that the rest of the way," said catcher Ramon Hernandez. "He pitched pretty good, especially here in this ballpark with the close wall, there are a lot of right-handers. I think he pitched very well, way better than the last couple of outings. ... Hopefully, he can be more consistent like he did tonight and there are going to be good results."

The game all turned in the sixth, when Olson turned a one-run lead into a three-run deficit. The Red Sox tied the game on back-to-back doubles, and Olson walked Jeff Bailey to keep the rally alive. Coco Crisp followed with a single to center, and Jacoby Ellsbury reached on an infield hit. That was it for Olson, and two more runs scored after he left.

"Early in the game, Olson was ... trying to establish his fastball," said manager Dave Trembley. "His command wasn't real good early, but then he kind of found it. In the sixth when we took the lead, he went away from it. In the entire sixth inning, I think he threw 27 pitches, and 20 of them were offspeed or breaking balls. I think he got out of his rhythm somewhat."

Olson owned up to that criticism, but Hernandez took responsibility for the tactical decision. The veteran backstop said that Olson had to change up his strategy to survive, and he defended the approach even if it didn't work.

"You've got to pitch differently," he said. "You just can't keep pitching the same way, especially against a team like Boston. They got hitters, they're veteran guys [and] they know how you've been pitching them. Sometimes you've got to pitch them differently every time they come up. You've really got to try to pitch a little backwards, back-and-forth."

Olson fell to 0-4 with a 7.76 ERA in six career starts against Boston, and more importantly, he helped keep a sordid trend alive for the Orioles. Baltimore has walked at least seven batters in four straight games, and Olson was responsible for five of them on Monday. Dennis Sarfate walked three more, and he also gave up a game-breaking hit to Dustin Pedroia.

The key play, though -- according to both Olson and Trembley -- was the walk to Bailey in the sixth.

"You've got to stick with what you know, stay [throwing] hard and work ahead of batters," said Olson. "You look at the top of the order coming up pretty soon, [and] definitely when you hit the bottom of the lineup, not to take anything way from them, but you tend to want to be more aggressive and have those two outs and just try to put somebody away."

"I thought the walk to Bailey in the sixth was the one that really hurt," said Trembley. "You walk Bailey with two outs [and] you can't get the third one. But more importantly than that, Olson gets out of the game and you bring in Sarfate and we can't get the third out. It was set up, I thought, pretty good when you've got 7-8-9 coming up and you've got a [tie game].

"We had the lead and we needed to put a zero up after we scored in the sixth. That didn't happen."

Baltimore had some bright spots Monday, chief among them the return of center fielder Adam Jones. The 23-year-old homered over the Green Monster on the first pitch he saw in the first inning, briefly giving the road team a lead. Juan Castro and Kevin Millar both added solo homers for the Orioles, who lost for the 11th time in their last 13 games.

Baltimore pushed the tying run to the plate in the ninth inning, but Jonathan Papelbon stranded two runners on base with game-ending ground ball. That resulted in his 35th save, and in the road team's fourth straight loss. The Orioles did get their center fielder back, though, and Trembley was pleased to be able to write his name in the lineup again.

"Only the special ones can do that," Trembley said of the home run. "We like to think he's going to be something real special for us in years to come. You know, to his credit, he worked real hard. It's a good way for him to get started."