MLB.com's No. 19 Prospect, Britton entered Wednesday's game in the third inning and tossed two scoreless frames in the Orioles' 6-5 win over the Philadelphia Phillies in Wednesday's Grapefruit League action.
The 23-year-old southpaw gave up a base hit to Placido Polanco, the first batter he faced, and Polanco moved to second on a wild pitch. Britton talked things over with catcher Jake Fox before finding his groove.
"It was all nerves out there," Britton admitted to MLB.com. "[Fox] told me a funny joke actually. I think he wanted to settle me down. He knew I was excited to be out there and stuff like that. I don't even know what joke it was."
He induced a dribbler back to the mound off the bat of Raul Ibanez and then struck out Ryan Howard.
"...He swung and missed the first fastball, [and] I saw him look at me kind of like [impressed], because I had some pretty good movement on that fastball," Britton said. "So I was like, 'alright well, I know I can pretty much go after him with those.'"
Britton got Ben Francisco out on a grounder to short to end the inning.
Shane Victorino beat out a bunt to start the fourth, but Britton again got around the leadoff baserunner. He got John Mayberry to pop out to first and retired Brian Schneider and Brian Bocock on ground balls.
The Orioles picked Britton out of high school from the Fort Worth, Texas, suburb of Weatherford in the third round of the 2006 Draft. He was 10-7 with a 2.70 ERA between Double-A Bowie and Triple-A Norfolk last year and may make his Major League debut at some point this season.
First base prospect Joe Mahoney delivered a hit for Baltimore, and Chris Tillman, who started the game and picked up the win, gave up a run on three hits and a walk over two innings.
Phillies prospects Tuffy Gosewisch, Michael Martinez and Harold Garcia each saw action for Philadelphia. Mayberry and Martinez hit back-to-back homers in the ninth inning, and Garcia scored a run.