TORONTO -- Shane Victorino played a huge part in Boston's latest comeback win.
It was the 19th time in 72 victories this season that the Red Sox have won in their final at-bat, meaning more than a quarter of their wins have come at the last opportunity.
It was also the 28th comeback win of the year for the AL East-leading Red Sox, who have overcome deficits in seven of their past nine victories.
"Much like we've seen of late here, if we get down early we continue to grind, continue to be relentless at the plate, provide or build opportunities," manager John Farrell said.
Few players have been as vital on that front as Victorino.
"He's a huge piece to why we're playing good baseball," infielder Dustin Pedroia said. "He's a winning player and a big reason why our team has been successful."
Jacoby Ellsbury grounded into a fielder's choice, with Middlebrooks forced at second and Saltalamacchia advancing to third.
Ellsbury stole second before Victorino grounded a two-run single up the middle.
"He's a very good player," Farrell said. "He's going to find a way to contribute, find a way to make a play."
Koji Uehara (3-0) worked 1 1/3 innings for the victory as the Red Sox won for the ninth time in 13 games at Rogers Centre, and rebounded after losing three of four at Kansas City last weekend.
"It was a big win for us to go out there and pull that one out," Boston starter Ryan Dempster said.
Arencibia's blast spoiled a strong performance by Dempster, who allowed one run and four hits in seven innings. Unbeaten in nine starts, Dempster walked two and struck out four.
"I felt like I was able to make pitches when I was behind in the count, which is huge," Dempster said. "I had a real good split tonight, that's probably what kept them off balance more than anything.
Recalled from Triple-A Buffalo to face the Red Sox in his first Blue Jays appearance since Aug. 2, Todd Redmond allowed three hits in 5 1/3 shutout innings. He walked one and struck out five.
"We've had some good pitching these last few days but our offense has just dried up," Toronto manager John Gibbons said.
The Blue Jays opened the scoring in the fifth when Brett Lawrie hit a one-out double, went to third on a fly ball and scored on an RBI single by Arencibia, whose hit snapped an 0-for-23 slump.
Reyes walked to begin the bottom of the sixth and went to second on Rajai Davis' grounder. One out later, third base coach Luis Rivera waved Reyes around on a sharp single to right by Encarnacion, but Victorino made a strong throw to the plate to retire Reyes and end the inning.
For Victorino, it was his eighth assist of the season, the most by a Red Sox right fielder since Trot Nixon had nine in 2005.
"To me, defensively, he might be the best right fielder in baseball right now, just because of his range and his ability to throw," Farrell said.
Having kept the deficit at one, the Red Sox took the lead with a two-run, three-hit seventh. Cecil left after striking out Saltalamacchia but Middlebrooks doubled off Sergio Santos, then scored on Ellsbury's single.
Ellsbury went to third on Victorino's grounder and scored on a base hit by Dustin Pedroia.
- Red Sox RHP Clay Buchholz, out since June 9 with a neck strain, is set to throw what manager John Farrell called an "aggressive" bullpen session Wednesday, including getting up and down between sets of pitches to simulate inning breaks.
- Blue Jays RHP Josh Johnson (forearm) was placed on the 15-day DL and RHP Thad Weber was recalled from Triple-A. RHP Esmil Rogers, demoted to the bullpen last week after nine winless outings, will get the start Wednesday.
- Boston LHP Matt Thornton (strained right oblique) felt fine after throwing on flat ground Tuesday.
- Toronto OF Colby Rasmus (strained left oblique) missed his second straight game.
- Red Sox C David Ross (concussion) went 0 for 3 with three strikeouts in five innings at Triple-A Pawtucket on Tuesday. Ross is scheduled to DH for Pawtucket on Wednesday.