Edwin Encarnacion's fifth career grand slam helped the Toronto Blue Jays beat the Baltimore Orioles, 12-6, in the opener of a four-game series.
J.P. Arencibia added a two-run homer and four RBI for the Blue Jays, who have won three of four. Emilio Bonifacio, Brett Lawrie and Colby Rasmus each knocked in a run.
Toronto starter Brandon Morrow (2-3) allowed six runs on 10 hits while striking out five over seven-plus innings.
Manny Machado hit three doubles and knocked in two runs for the Orioles, who had a two-game winning streak snapped. Adam Jones, Nick Markakis and Chris Davis all hit solo homers.
Baltimore starter Kevin Gausman (0-1), making his MLB debut, gave up four runs on seven hits while striking out five over five innings. Gausman, the fourth overall pick in the 2012 First-Year Player Draft, went 2-4 with a 3.11 ERA in eight starts with Double-A Bowie this season.
The Orioles scored a pair of runs in the third inning. Chris Dickerson and Nate McLouth each singled before pulling off a double steal. Machado followed with a two-run double to left.
Davis' league-leading 15th homer in the fourth gave Baltimore a 3-0 edge.
Toronto responded with eight unanswered runs, starting with a pair of runs in the bottom half of the fourth. Adam Lind led off with a double to right and raced home on Arencibia's double to left. Lawrie reached base on a bunt single and Rasmus walked to load the bases with no outs. Bonifacio's sacrifice fly gave the Blue Jays a 4-3 lead. Gausman retired the next two batters to prevent further damage.
Gausman, though, gave up a homer to Arencibia in the fifth. Lind hit a two-out single and scored on Arencibia's homer to left.
The Blue Jays broke things open in the sixth on Encarnacion's grand slam. Troy Patton issued consecutive two-out walks to Munenori Kawasaki and Melky Cabrera. Pedro Strop came in from the bullpen and walked Jose Bautista to load the bases. Encarnacion stepped to the plate and smacked Strop's offering off the left-field foul pole, making it an 8-3 contest.
The Orioles got one run back in the seventh. J.J. Hardy hit a ground-rule doubled to left, moved to third when Dickerson flied out and scored on Alexi Casilla's sacrifice fly.
Markakis and Jones hit back-to-back homers in the eighth to cut the gap to 8-6.
The Blue Jays, though, created some distance again by scoring four runs in the bottom half. Anthony Gose led off with a single and moved to second when Bautista reached first on shortstop Hardy's fielding error. With Encarnacion batting, the ball got past Matt Wieters. The Baltimore catcher picked up the ball and fired to second, which allowed Gose to try for home. Gose just beat the tag at the plate.
Encarnacion and pinch-hitter Mark DeRosa walked to load the bases with no outs. Toronto then scored three more runs on Arencibia's groundout, Lawrie's base hit and Rasmus' sacrifice fly.
Prior to Thursday's game, the Orioles selected the contract of Gausman from Bowie, optioned pitcher Jake Arrieta to Triple-A Norfolk and designated pitcher Alex Burnett for assignment ... Morrow improved to 4-3 lifetime against Baltimore ... Orioles manager Buck Showalter turned 57 on Thursday ... Gausman is the 11th different pitcher to start for Baltimore this year ... The Blue Jays announced Thursday that prospect Sean Nolin will start for the club Friday against the Orioles.