NEW YORK -- The Yankees were huddled in the center of the infield, still trying to decide what to make of Joba Chamberlain's abbreviated evening, when Alfredo Aceves began to limber in the bullpen.

Such is the responsibility of the long reliever, who never knows when he'll be called upon to help save the day. In this case, Aceves did so while some fans were still searching for parking, hurling 3 1/3 scoreless innings in the Yankees' 7-4 victory over the Orioles on Thursday.

The winning effort, coming after Chamberlain was struck by a first-inning line drive, translated into a ninth consecutive win for the smiling and confident Yankees, who have now posted back-to-back sweeps at Yankee Stadium and are beginning to feel at home in their new digs.

"We are playing very good, and that's why we're winning," Aceves said. "Nine straight wins -- we'll go for 10 tomorrow."

It has been a warm and fuzzy homestand for the Bombers, who are beginning to see all facets of their game translate after a shaky opening act, posting their first nine-game winning streak since June 5-14, 2007.

But they had little to celebrate in the first inning when Chamberlain was struck in the right knee by an Adam Jones liner, taking all the steam out of speculation about possible retaliation against Aubrey Huff for the slugger's exaggerated fist pumps following a May 10 homer.

Though Chamberlain picked up the ball hit by Jones and threw to first base for the out, his knee quickly stiffened and Yankees manager Joe Girardi eyed Chamberlain limping as he moved to cover third base two batters later.

That was the end of the night for Chamberlain, as Aceves came in having offered two innings of relief the previous night, escaping the inning and hurling three more scoreless frames as Chamberlain underwent negative X-rays in the bowels of the ballpark.

"That's a tough game, because you're asking an awful lot out of your bullpen," Girardi said. "We knew that we had 'Ace' for about 50 pitches, and he was a huge component in our win tonight, because he gave us some distance."

The Yankees didn't have to worry much about support behind Aceves and their bullpen, as New York put a pounding on Baltimore starter Adam Eaton, leading the long-gone starting pitcher to cheer from afar.

"You've got to tip your cap to those guys, especially knowing that we were short down there," Chamberlain said. "The offense did a good job picking us up, too, knowing what was going on."

Cano and Mark Teixeira drilled back-to-back RBI doubles, and Melky Cabrera stroked a two-run double to left. Cano added a two-run homer in the second inning, his eighth of the season and the second time in two games he has reached the right-field seats at Yankee Stadium.

"We're playing unbelievable," Cano said. "We're doing everything we've got to do. Our pitching is great, and everything is coming together."

Hideki Matsui added a solo homer, his fifth, off Eaton in the fifth inning. Eaton was charged with seven runs on eight hits in 4 2/3 innings.

Over the nine-game winning streak, the Yankees are hitting .370 (27-for-73) -- including five homers -- with runners in scoring position, compared with .243 prior. Meanwhile, New York's once-beleaguered bullpen combined to hold Baltimore to four runs on 10 hits in 8 1/3 innings -- good enough on this night.

"We're getting deeper into the season and the guys are getting looser, I guess," said Yankees closer Mariano Rivera, who hurled a perfect ninth inning for his ninth save. "All the troubles were early. During the season, you're going to have periods of time of trouble.

"It doesn't mean the bullpen is bad. It happens. Pitchers go through it, and hitters go through it, too. I believe that we just have to continue to do what we're capable of doing."

Aceves claimed he was fortunate -- "I made, like, three or four mistakes today; I got lucky," he said -- but he got the ball to the sixth inning before the Orioles touched Jonathan Albaladejo for four runs in 2 1/3 frames. Rivera said he knew Aceves would be able to keep the Yankees in the game.

"I know he's capable to do it," Rivera said. "He has a lot of experience. Pitching a lot in Mexico helped him, with a lot of veterans. He's done a tremendous job."

Brian Roberts hit a solo homer, his sixth, on Albaladejo's first pitch, and Ty Wigginton stroked a pinch-hit two-run double in the sixth, Baltimore's first pinch-hit of the season.

Nick Markakis added a solo home run, his seventh, on Albaladejo's final pitch. But Jose Veras evaded trouble in recording five outs to set things up for Rivera, who set the side down in order to polish off career save No. 491.

"We're playing together -- we're playing as a team," Rivera said. "We're doing everything and just having fun."

Bryan Hoch is a reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.