Mark Buehrle tossed six effective innings and handed Clay Buchholz his first loss of the season, as Toronto bested Boston, 4-2, in the middle test of a three-game series from Fenway Park.
"Steady Eddie, doing what he has been doing his whole career. You get 25 Buehrles and you are probably gonna have a good year," said Jays manager John Gibbons in praise of his starter, the most consistent on his staff.
Buehrle (12-9) scattered five hits and one run while fanning five, and three Toronto relievers held their hosts hitless over the final three frames. Casey Janssen was the last of the bunch, recording his 33rd save with a spotless ninth.
Adam Lind, Rajai Davis and J.P. Arencibia drove in a run each for the Blue Jays, who recovered from a 6-3 loss in Friday's opener.
Buchholz (11-1), tasked with taking the hill less than 24 hours after his club clinched the AL East title, also worked six innings but allowed three runs on six hits. The right-hander experienced his first defeat since Oct. 1, 2012 against the Yankees, then last of five straight setbacks to end the year.
"I feel good. The movement on all my pitches is there," Buchholz said. "It's just about the command and location and where to start it, which is sometimes hard to get better. The velocity is there and the body feels good."
Jonny Gomes and David Ross knocked in runs for the Red Sox, who have dropped three of their last five.
The Jays broke through for three runs in the fourth. Brett Lawrie kept the frame alive with a two-out single, then scored when Lind followed with a double. Moises Sierra's single put runners on the corners, then Davis singled in another run and Sierra scored on a Buchholz throwing error.
Boston finally answered in the sixth as Gomes singled home Stephen Drew with one down, but Daniel Nava grounded into an inning-ending double play with runners on the corners.
It was 3-2 in the home seventh, as Xander Bogaerts reached second on Lawrie's error, moved up on a wild pitch and scored on a Ross groundout.
Toronto picked up an insurance run in the top of the ninth, as Davis worked a leadoff walk, was sacrificed to second and came around on an Arencibia base hit.
Dustin McGowan, Sergio Santos and Janssen combined to send down the final seven Red Sox batters to finish off the win.
Buehrle's effort pushed him over the 200-inning mark for the 13th straight season ... The 34-year-old lefty began his career in 2000 with the White Sox, pitching only 51 1/3 frames in 28 appearances ... Despite the loss, Boston still leads the season series, 10-8, winning five of nine at home ... Prior to the contest, the Jays announced that outfielder Colby Rasmus was placed on the disabled list, ending his season. The 27-year-old left Friday's game after being struck in the side of the face by a teammate's errant throw ... Gibbons was ejected in the eighth inning for arguing a call at first base.