Edwin Encarnacion made sure the Toronto starter got the win he deserved.
Morrow had a season-high nine strikeouts over six shutout innings and Encarnacion smacked his fourth career grand slam as Toronto blanked the Seattle Mariners 7-0.
"That's probably my best outing so far," Morrow said. "I think it came down to fastball command and I think I had a real good slider today."
Morrow (2-1) allowed five hits and didn't walk a batter as the Blue Jays improved to 11-10 in front of 30,765 fans at Rogers Centre. Jason Frasor, Darren Oliver and Carlos Villanueva each pitched an inning of relief to complete the Jays' first shutout of the season.
Toronto loaded the bases in the eighth inning and Encarnacion tagged the first pitch he saw from Hisashi Iwakuma over the wall in right field. The designated hitter said he feels more comfortable this season now that he's using a shorter, more compact swing.
"That's No. 1, that's the key," Encarnacion said.
He also doubled in the sixth inning and now has 14 extra-base hits and an impressive .302 average this season.
"He's locked," said Jays first baseman Adam Lind. "He's carried this offence pretty much for the whole month."
Seattle (11-11) fell back to the .500 mark and had its four-game winning streak come to an end.
Toronto scored three runs in the third inning off Mariners starter Kevin Millwood (0-2), who allowed seven hits and one earned run over seven innings.
Yunel Escobar got the first rally started with a one-out single before moving to third on a single by Kelly Johnson. Jose Bautista followed with a hard-hit grounder to third base that handcuffed Kyle Seager, who was charged with an error.
Lind sliced a ground-rule double down the left-field line to score Johnson and move Bautista to third. Encarnacion hit a sacrifice fly that scored Bautista but the Mariners cut the throw off from the outfield to get Lind in a rundown for the third out.
Seattle was able to hit the ball hard a few times but Morrow remained steady throughout his 104-pitch outing.
He didn't get rattled in the fifth inning when Johnson dropped a popup after calling off Lind on the play. The error left runners on the corners but Morrow struck out Brendan Ryan and got Chone Figgins to ground out to end the threat.
Seattle put two runners on in the sixth but Morrow used a 97-m.p.h. fastball to strike out Jesus Montero for the final out.
"When he's throwing that hard slider and mixing in his secondary stuff the way he did today — as well as spotting up his fastball — you're going to have your work cut out," said Seattle manager Eric Wedge.
In the eighth, Johnson singled to centre field and moved to third on a ground-rule double by Bautista. Lind was intentionally walked before Encarnacion smacked his sixth homer of the season.
Toronto outhit Seattle 10-6 on the day. The game took two hours 45 minutes to play.
Notes: Brett Lawrie of Langley, B.C., singled in the seventh inning to extend his hitting streak to eight games. ... Encarnacion's last grand slam came on April 13th, 2009 against the Milwaukee Brewers. ...The teams will play the rubber game of the three-game series Sunday afternoon. Henderson Alvarez (0-2) is scheduled to start for the Blue Jays against Jason Vargas (3-1). ... Morrow was selected by the Mariners with the fifth overall pick of the first-year player draft in June 2006. The Blue Jays acquired the Santa Rose, Calif., native from Seattle in December 2009. The Mariners got right-hander Brandon League and outfielder Johermyn Chavez in return. ... Seattle has lost five of its last six games at Rogers Centre. ...