BOSTON >> The Toronto Blue Jays’ sputtering finish to the month wiped away nearly all they gained during an 11-game winning streak.

Josh Thole misplayed Shane Victorino’s hard grounder to first for an error, allowing the winning run to score in the ninth inning Sunday that lifted the Boston Red Sox to a 5-4 win over the Blue Jays.

Three weeks ago, the Blue Jays were buried in AL’s East basement, trailing the first-place Red Sox by 12 games. They went on a club-record tying winning streak and climbed to five games behind Boston.

Now, the last-place Blue Jays are back in another deep hole after losing five of seven games to close the month. Toronto is 8 1-2 games behind the Red Sox.

“It was frustrating,” Blue Jays manager John Gibbons said. “That might be the most frustrating loss of the year right there, to be honest with you, because of who we were playing and where we’re at.”

Jose Bautista tied the game in the ninth against Koji Uehara (1-0) with a solo homer, his 19th of the season and third in two games.

But the Red Sox pulled out their third win in the four-game series.

The Blue Jays had dropped two of three at the Tampa Bay Rays after their streak and before coming to Boston.

“I think even in Tampa you saw games we were winning in that stretch,” Toronto starter Mark Buehrle said. “Guys are hitting the (heck) out of the ball and it goes right to someone. That’s why the season’s long and you play so many games. You go through ups and downs. You get lucky. It seems like it caught us the last couple of games.”

The Blue Jays, a game under .500 at the halfway point (40-41), finished June 17-9.

“Hopefully we can go on some more winning streaks,” Buehrle said.

Brandon Snyder singled with one out in the bottom half of the ninth against Juan Perez (1-1), Jacoby Ellsbury walked and Casey Janssen relieved. Jonathan Diaz ran for Snyder and Thole, who had entered in the third when Adam Lind left with back tightness, couldn’t handle Victorino’s shot.

Thole, a catcher, played behind the plate 284 of his 285 times in the field before Sunday. His other position was at first for the Blue Jays earlier this season.

“I’ve played first base,” said Thole, who played first at Triple-A Buffalo. “That’s what I’m here for, spots for a chance to play first. I’ve got to catch the ball and make an out.”

Boston won for the fifth time in six games and improved to an AL-best 50-34.

Jose Reyes homered for the Blue Jays, his second of the season and first since April 5. Reyes returned Wednesday after missing 66 games because of a severely sprained left ankle.

Boston starter Ryan Dempster allowed two runs, seven hits and three walks in 5 1-3 innings. Buehrle gave up four runs and seven hits in six innings.

Ryan Lavarnway’s RBI double and Snyder’s two-run double gave Boston a 3-0 lead in the second. It was the first big-league hit of the season for Snyder, brought up from Triple-A on Tuesday when struggling third baseman Will Middlebrooks was sent to Pawtucket.

Colby Rasmus’ RBI single and Maicer Izturis’ run-scoring forceout cut the gap to 3-2 in the fourth.

After Jonny Gomes’ RBI double boosted the margin in the fifth, the Blue Jays loaded the bases with no outs in the sixth on a walk to Thole and singles by Rajai Davis and Rasmus. Dempster got J.P. Arencibia to pop out, and Craig Breslow retired Izturis on a popout and then struck out pinch-hitter Emilio Bonifacio.

Reyes homered leading off the seventh.

NOTES: Gibbons said INF Mark DeRosa “did something to his neck in BP” and was unavailable. … Davis’ stolen base in the fourth was his fifth in three days. … Boston SS Stephen Drew missed his second game with a right hamstring injury. … After a day off Monday, the Red Sox begin their last series of a nine-game homestand with the first of three against San Diego. Robbie Erlin (1-0) pitches for San Diego against John Lackey (5-5). … The Blue Jays open a four-game series at home against Detroit on Monday with R.A. Dickey (7-8) pitching against Jose Alvarez (1-1). Boston became the first AL team to reach 50 wins in a season for the first time since 2009.