Joe Saunders' second start as an Oriole went much better than his first.
Saunders pitched into the seventh inning and the Orioles took the opening game of a three-game series against the Toronto Blue Jays, 4-0.
Saunders (1-1), who gave up seven runs -- six earned -- in 5 1/3 innings after coming over from the Arizona Diamondbacks, gave up three hits and two walks in 6 1/3 innings. He did not allow a base runner until surrendering a two-out single in the sixth inning.
"Pitchers are creatures of habit," Orioles manager Buck Showalter said. "He's getting back in a routine."
Nick Markakis doubled home a run and scored to send the O's to their eighth win in their last 10 games.
J.A. Happ (3-2) had a string of three straight winning decisions snapped after giving up three runs -- two earned -- on six hits with nine strikeouts in five-plus innings.
"He's got good late life," Showalter said. "He bent, but he didn't break. He gave them a chance to win today.
"I was trying to be pretty selective with the pitches I threw to keep us in the game the best I could," Happ said. "Unfortunately, they chased me out of there quicker than I would have liked."
Baltimore took the lead in the second inning after Manny Machado lofted a fly ball down the right-field line. Moises Sierra was unable to make a sliding catch, allowing the ball to roll to the fence and Machado to reach third.
After the error, Nate McLouth dropped down a bunt to score Machado and gave the O's an early lead.
The Orioles tacked on a pair of runs in the fifth inning. Robert Andino led off with a base hit and scored when Nick Markakis sliced a double down the left-field line. J.J. Hardy knocked in Markakis with another double to left, opening up a three-run advantage.
Adeiny Hechavarria singled in the sixth to finally give the Blue Jays a base runner but, after reaching second when Rajai Davis walked, he was stranded.
Edwin Encarnacion walked and Adam Lind singled to start the seventh inning. After Yunel Escobar grounded into a fielder's choice, Kelly Johnson ripped a single to right to load the bases and chase Saunders from the game.
Luis Ayala came on to strikeout Sierra and got an inning-ending pop up from Jeff Mathis to escape the jam.
Baltimore capped the scoring in the eighth inning when McLouth was hit by a pitch, reached second when Andino walked and scored on a Hardy base hit.
Pedro Strop and Jim Johnson retired the Blue Jays in order in the eighth and ninth innings to wrap up the win.
Baltimore won its 75th game for the first time since 2004 ... The Orioles lead the season series 8-4 ... After a stretch in which they lost 23 of 25 games at Rogers Centre, the Orioles have gone 6-8 in their last 14 games in Toronto ... Baltimore is 22-14 in games started by opposing left-handers ... The O's are 26-13 in day games ... Baltimore is 16 games over .500 for the first time since the end of the 1997 season ... The Blue Jays have lost 11 of their last 15 games ... Prior to the game, Toronto recalled pitcher Brett Cecil, who gave one run in two innings, from Triple-A Las Vegas and reinstated pitcher Jeff Frasor from the 15-day disabled list ... In 49 games since moving to the leadoff spot, Markakis is hitting .343 with 13 doubles, 31 runs scored and 27 RBI.