When Joe Mahoney arrived in Southern California on Thursday to fill the Orioles' empty roster spot created when Chris Tillman was optioned to the minor leagues, he didn't know when — or if — he'd see his first major-league action before the All-Star break.

On Saturday, he received his answer. Mahoney made his first major-league start at first base against the Los Angeles Angels and ace right-hander Jered Weaver.

"It's pretty special, the first time, and it's against a good pitcher," Mahoney said. "You come in and you see the righties and lefties and the matchups like that, so I figured today would be one of my good chances to play. Now's the time to show up and help them out."

Mahoney was hitting .256/.307/.355 with 24 doubles, five home runs and 38 RBIs in 85 games at Triple-A Norfolk, including a .306 batting average in his last 10 games.

"Hopefully he can follow with the kind of first major league start that our pitcher had last night," Orioles manager Buck Showalter said, referring to rookie Miguel Gonzalez's seven-inning, one-run, three-hit game on Friday. "Joe has been a little streaky down there and we caught him when he was swinging it pretty good. I wanted to give him a quick opportunity. I think he understands that he'll probably head back after the break, but let him get a taste of it before he goes back."

The Orioles' sixth-round pick in 2007, Mahoney was the Orioles minor-league player of the year in 2010. He had been at big-league spring training the past two seasons, but struggled to stay healthy.

"I'm just trying to keep it like a normal day," said Mahoney, who had a half-dozen family members in attendance. "Just try to keep everything as normal as possible and try to do everything like I do every day no matter where I am.

Mahoney flied out to right off Weaver in his first at-bat.