"You can't control who they bring or who they don't bring," Britton said. "It's Spring Training, you know there are obviously going to be guys in there who might not be in the big leagues, but they've all got a bat in their hands and they can all do damage. So you just execute your pitches, and that's what we tried to do today."
Britton, whose longest previous outing this spring was two innings, retired the first six batters he faced before giving up a leadoff single to Mitch Maier in the third. He then pitched around a Manny Machado error to strand two runners and keep the game scoreless heading into the fourth, where he lost some of his command.
After erasing a leadoff walk to Jackie Bradley by inducing a double-play ball from Ryan Lavarnway, Britton issued his second walk of the inning to David Ross, prompting manager Buck Showalter to go to the bullpen. Reliever Zach Petersime took over and retired the only batter he faced, keeping the game scoreless.
It would remain that way until the fifth inning, when Red Sox prospect Bryce Brentz, making his first appearance of the spring, crushed a homer to left-center field off Luis Ayala.
Boston's lead would be short lived, however, as the Orioles quickly answered in the bottom half of the inning. With two outs and nobody on, center fielder Nate McLouth started the rally with a double to right field, then came around to score one batter later on a Brian Roberts single.
The Red Sox pulled ahead on a solo shot by J.C. Linares and an RBI single by Ronald Bermudez in the top of the 10th, but the O's tied it in the bottom half of the frame on Ryan Flaherty's two-run homer with two outs.
Up next: Jake Arrieta will look to further improve his bid for a spot in the O's starting rotation Saturday when Baltimore travels to Dunedin to take on the Blue Jays at 1:05 p.m. ET (listen on Gameday Audio). The right-hander is coming off his best performance of the spring, tossing four shutout innings Monday against the Pirates while allowing just two hits and striking out five. Left-handers Troy Patton and Daniel Schlereth, along with right-hander Adam Russell, are also slated to take the mound.
Paul Casella is a reporter for MLB.com. Follow him on Twitter @paul_casella. This story was not subject to the approval of Major League Baseball or its clubs.