TORONTO (AP) -- An unlikely rookie is leading the Detroit Tigers in wins.
Ivan Rodriguez had four hits and Renteria scored twice for the Tigers.
Galarraga (2-0) has won back-to-back starts since being called up from Triple-A Toledo last week to replace Dontrelle Willis, sidelined by a hyperextended knee.
Acquired in an offseason trade with Texas, Galarraga won't face the Rangers when they visit Detroit this week but still had a message for his former team.
"They made a mistake," he said, laughing.
The 26-year-old Galarraga blanked the Blue Jays on three singles for 5 1/3 innings. He struck out four and walked four.
"He had a lot of late movement," Blue Jays second baseman Aaron Hill said. "He was running pitches in, he was doing well with his slider."
Galarraga, who beat Cleveland last week, lowered his ERA to 1.50. He has not allowed a hit to a right-hander in 21 at-bats since joining the Tigers.
"He's got a good sinker, a good slider," Rodriguez said. "He was able to use them today and make the right-handed hitters hit the ball on the ground."
The Blue Jays loaded the bases against Galarraga in both the third and fourth innings but failed to score each time.
"I was trying to be more aggressive when I had runners on base," Galarraga said. "When the bases were loaded, I tried to be aggressive in that moment."
"His control wasn't as good today, but he dodged a couple of bullets," Tigers manager Jim Leyland said.
Toronto finished 0-for-8 with runners in scoring position Monday and went 7-for-56 (.125) with runners in scoring position on this six-game homestand, winning just twice.
Gregg Zaun hit a leadoff homer in the ninth Toronto off Todd Jones. Zaun shook his head after fouling off a high 3-2 pitch and then hit the next delivery over the right-field wall for his first home run of the season.
The Tigers gave Galarraga all the support he needed with a four-run second off Shaun Marcum (2-1). Ryan Raburn hit a two-run single, Brandon Inge followed with a sacrifice fly and Rodriguez capped the burst with an RBI single.
"We got some big hits today and took advantage of our opportunities," Leyland said. "That's huge, that's what you've got to do."
Renteria led off the sixth with his third homer of the season and second of this series.
Marcum lost for the first time in four starts, allowing five runs in 5 2/3 innings, his shortest outing this season. He walked a season-high four and struck out two.
"Obviously we didn't bring anything to the table today," Hill said. "Marcum didn't have his best day, we didn't hit, didn't play defense. It's one of those games that's going to be easy to forget."
Detroit second baseman Placido Polanco had an MRI on his aching back Sunday, revealing no damage. Polanco has started medication and could be ready to play again Tuesday after missing four of the past five games. ... Tigers DH Gary Sheffield (sore shoulder) missed his second straight game and will see a doctor once the team returns to Detroit. Sheffield had surgery to repair a tear in his right shoulder in October. ... Blue Jays outfielder Vernon Wells got the day off. ... Catcher Robinzon Diaz joined the Blue Jays on Monday, taking the roster spot of DH Frank Thomas, who was released Sunday.