Josh Thole's fielding error at first base enabled the winning run to score with one out in the bottom of the ninth inning as the Boston Red Sox edged the Toronto Blue Jays by a 5-4 count at Fenway Park.
Toronto had fought back from a 4-2 deficit to draw even on solo homers by Jose Reyes and Jose Bautista, with the latter coming off Red Sox closer Koji Uehara (1-0) with one out in the top of the ninth.
Brandon Snyder finished 2-for-4 and had a two-run double earlier for Boston, while Jonny Gomes and Ryan Lavarnway each contributed RBI doubles to help the Red Sox take three of four matchups from their AL East rival in the weekend set and prevail for the fourth time in five meetings overall.
"This team reminds me of some of the winning teams that I've played on, the resiliency, the playing until there are 27 outs, no matter how many runs you're down," said Red Sox outfielder Shane Victorino, who hit the ground ball that Thole botched to allow pinch-runner Jonathan Diaz to score from second. "That's the kind of stuff that's important, and to me, what's made this team how good we are and where we are, in first place, and with 50 wins."
Bautista's game-tying blast capped a 3-for-5 day at the plate, with Colby Rasmus collecting two hits and an RBI for the Blue Jays.
Edwin Encarnacion and Rajai Davis both went 2-for-5 with a run scored in the loss, Toronto's fifth in seven outings on a seven-game road trip in which the team entered having ripped off 11 consecutive victories.
Bautista sent the game to the bottom of the ninth by jumping all over Uehara's second-pitch spinner and launching it well over the Green Monster for a 4-4 deadlock, but Boston quickly threatened in its portion of the inning after Snyder singled off Juan Perez (1-1) with one out and Jacoby Ellsbury worked a walk to force Jays manager John Gibbons to summon closer Casey Janssen to the mound.
Victorino greeted Janssen with a chopper to Thole, normally a catcher pressed into playing first after Adam Lind had to be removed after three innings with back tightness. The ball trickled through Thole's legs and into right field, with Diaz easily coming home from second.
"Just didn't catch it," said Thole. "I need to catch the ball. That's the bottom line. "It sucks, but I've just got to catch the ball and make an out."
Jays starter Mark Buehrle lasted six innings and gave up four runs, three of which came during a rough bottom of the second in which Boston put up four hits to gain the early upper hand.
Mike Napoli and Daniel Nava started the Red Sox' half of the frame with singles before Lavarnway's fly ball down the right-field line dropped in for a ground-rule double to bring in the initial run. Two batters later, Snyder drove a changeup into the gap in left center to knock home both runners for a 3-0 advantage.
Boston's Ryan Dempster set down the first eight Toronto hitters, but ran into trouble in the fourth as the Blue Jays inched closer.
Encarnacion and Davis singled in front of Rasmus' one-out hit to right that cut the deficit to 3-1. After a walk to J.P. Arencibia loaded the bases, Davis crossed the plate when Maicer Izturis beat out a potential double-play ball.
Boston increased its lead to 4-2 when Ellsbury singled and came around on Gomes' double high off the Monster, though Reyes would pull Toronto back within a run with his solo blast off Craig Breslow in the seventh.
The Blue Jays missed out on a scoring opportunity an inning prior, having loaded the bases with none out on a walk and singles by Davis and Rasmus. However, Dempster was able to get Arencibia to pop up harmlessly before giving way to Breslow, who did the same to Izturis before striking out pinch-hitter Emilio Bonifacio.
"It's a situation you hate to put that on anybody to come in there, and Bres just made some big pitches there and got out of that unscathed," said Dempster, who worked around seven hits and three walks to limit Toronto to two runs over his 5 1/3-inning stint. "You need those during the year."
Buehrle has now posted three losses and three no-decisions since his last win at Fenway, which came on August 15, 2004 while a member of the White Sox ... Ellsbury ended 1-for-3 and is batting .404 (19-for-47) during an 11-game hitting streak ... Boston shortstop Stephen Drew sat out a second straight day with a sore hamstring ... Dempster had a string of six consecutive quality starts end after failing to complete six innings ... The Red Sox improved their MLB-best record in day games to 17-9.