BALTIMORE - Orioles starter Chris Tillman gave the Red Sox numerous chances to score early in Friday night's game at Camden Yards.
Boston didn't capitalize, Tillman settled down, and the large image in the Red Sox's rearview mirror crept a little bit closer. Tillman pitched six scoreless innings and Chris Davis hit his major-league-leading 22nd homer as the Baltimore Orioles defeated the Boston Red Sox 2-0 Friday night.
The victory moved the Orioles (39-29) within 1 1/2 games of the first-place Red Sox (41-28) in the American League East.
"You've got to be careful. Every spot in their lineup has potential," Orioles manager Buck Showalter said. "You can't ever drop your guard and I think, more than anything, Chris doesn't do that. He keeps pitching."
Manny Machado added two doubles and a single for Baltimore, which has taken the first two games of the four-game series and is 4-1 against Boston in 2013.
Tillman (7-2) allowed three hits and struck out three. He walked a batter in each of the first four innings, but kept Boston at bay, retiring eight straight at one point.
"I think early I struggled with command a little bit," Tillman said. "We were able to make an adjustment mid-game and I kind of went with (catcher Matt) Wieters from there and started attacking the zone a little quicker."
Tillman was lifted when Jose Iglesias led off the seventh inning with a double on his 106th pitch.
"He was frustrated," Showalter said of Tillman. "He was going to try and get the seventh, but he didn't get off to a good start."
Baltimore reliever Darren O'Day came on and retired Will Middlebrooks on a soft liner to second, struck out David Ross and got Jacoby Ellsbury to fly out to end the threat.
Tommie Hunter pitched a perfect eighth and Jim Johnson survived a hit batter in the ninth for his 24th save.
"We did get a couple of guys on base over the course of the game, but it was a night where we couldn't bunch anything together," Red Sox manager John Farrell said.
The Orioles' bullpen has thrown nine hitless innings against Boston in this series.
"You know when they come in the game they're going to do the job for us," Tillman said.
Boston starter Ryan Dempster (4-7), making his first career start at Camden Yards, allowed base runners in each of the first five innings, but limited the Orioles to single runs in the second and third innings.
He went 7 2/3 innings, allowing five hits while striking out four and walking five.
"The guy just pitched his tail off over there," Dempster said. "Sometimes you just get out-pitched, and there's really nothing you can do about it. We don't get shut out very often."
Dempster's lengthy start was welcome relief for the Boston bullpen after Thursday's 13-inning game.
"Ryan did a great job, threw a great game," Ross said. "That was a huge, huge performance."
Iglesias had two hits for Boston.
Both teams had numerous chances to score early. Boston stranded six base runners over the first four innings, and the Orioles wasted a one-out double by Machado in the first.
Davis opened the scoring when he led off the Orioles second and hit an 0-1 fastball from Dempster over the wall in left-center for an opposite field home run.
"I felt really good to stay through one the other way," Davis said. "I felt like the last couple of weeks I was really pulling off pitches, coming around the baseball. It's something I worked on a couple of days ago, trying to get back to driving the ball and hitting it where it's pitched."
Baltimore added a run in the third. With one out, Nate McLouth walked and Machado singled. McLouth went to third on a fly ball by Nick Markakis and scored when Adam Jones hit a slow roller to third and beat the throw from Middlebrooks at first.
NOTES: The Orioles announced that they have reinstated LHP Tsuyoshi Wada (elbow surgery) from the 60-day disabled list and have optioned him to Triple-A Norfolk. ... Both teams made moves to bolster their bullpens Friday in the wake of Thursday's game. The Red Sox recalled RHP Rubby De La Rosa from Triple-A Pawtucket and Baltimore recalled RHP Jake Arrieta from Triple-A Norfolk. ... Machado extended his hitting streak to 12 games with a first-inning double. ... Iglesias extended his hitting in games in which he has an official plate appearance to 15 with a fourth-inning single. ... The Red Sox traded infielder Pedro Ciriaco to the San Diego Padres for a player to be named later or cash considerations. Ciriaco, who was designated for assignment June 11, hit .216 in 51 at-bats for the Boston this season.