Toronto’s Alejandro Kirk, right, reacts as he tagged out at second base by Red Sox shortstop Trevor Story after trying to stretch a single into a double in the fifth inning on Saturday in Toronto. Chris Young/The Canadian Press via AP

TORONTO — Whit Merrifield hit a game-winning single in the 13th inning and the Toronto Blue Jays rallied to beat the Boston Red Sox 4-3 on Saturday.

Merrifield’s infield single off Mauricio Llovera (1-3) drove in Vladimir Guerrero Jr. from third base for Toronto’s fifth win in its last at-bat.

Chad Green (3-0) pitched one inning for the win.

Guerrero hit a solo home run and reached base five times as the Blue Jays ensured they would not lose ground in the AL wild-card race. Toronto began the day half a game behind Seattle for the third wild card spot.

“At this point in the year, any win is going to be a good confidence boost,” Merrifield said. “Hopefully it will be good momentum.”

Guerrero went 2 for 3 with three walks, one intentional. He has homered in three consecutive games for the fourth time in his career.

“What Vladdy has done the last couple of days is a big boost,” Merrifield said.

Rafael Devers hit a two-run home run, his 32nd, but Boston lost for the ninth time in 11 games. The Red Sox lost for the fourth time in 62 opportunities when leading after six innings.

Toronto used an intentional walk and an infield single to load the bases against Nick Robertson in the 10th, but Merrifield struck out to end the threat.

“When something like that happens you’re eager to get back up and try again,” Merrifield said. “Fortunately I got another chance and made it happen.”

Boston led 2-1 heading to the ninth but right-hander John Schreiber couldn’t close it out, blowing his second save in three chances.

Pinch-hitting for Matt Chapman, Toronto’s Cavan Biggio hit a one-out single and advanced on a wild pitch. One out later, Daulton Varsho lined a game-tying triple over the head of rookie center fielder Ceddanne Rafaela, who initially broke in on Varsho’s hit.

“It’s a mistake,” Red Sox Manager Alex Cora said of Rafaela’s play. “He’ll learn from it and be better for the next one.”

Schreiber sent it to extra innings by getting George Springer to ground out.

Boston’s Pablo Reyes hit an RBI single off Jordan Hicks in the top of the 12th but Bo Bichette tied it in the bottom half with a sacrifice fly off Zack Weiss.

Red Sox left-hander Chris Sale allowed one run and two hits in six-plus innings. The left-hander walked two and struck out 10.

“Definitely something to build off of,” Sale said.

Cora said he hasn’t seen Sale pitch better this year.

“I know he’s had some good games this season but for me, that was the best one as far as hitting his spots,” Cora said.

Sale departed after Guerrero’s leadoff home run in the seventh, his 24th.

Right-hander Josh Winckowski replaced Sale and got two outs but walked the bases loaded. Brennan Bernardino came on and retired pinch hitter Ernie Clement to end the threat.

Making his career-high 31st start, Blue Jays right-hander Chris Bassitt allowed two runs and four hits in seven innings.

Plate umpire Jordan Baker was struck in the left shoulder by a foul tip during Justin Turner’s at-bat in the top of the fourth. Baker received attention from Toronto’s trainer and was able to continue, but left after the eighth. Brennan Miller moved from second base to behind the plate in the ninth.

TRAINER’S ROOM

Red Sox: Boston put 1B Triston Casas on the 10-day IL because of right shoulder inflammation and recalled INF Bobby Dalbec from Triple-A Worcester.

Blue Jays: RHP Adam Cimber (shoulder) allowed one run and two hits in one inning in his first rehab appearance at Triple-A Buffalo on Saturday.

STARTING STRONG

Red Sox starting pitchers have allowed three or fewer runs in each of the past seven games.

WEB GEM

Springer raced into the right field corner to make a diving catch on Masataka Yoshida’s liner for the first out of the seventh.