BOSTON — Ezequiel Carrera hit a ninth-inning sacrifice fly to give Toronto the lead after the Red Sox tied it in the eighth on a balk, and the Blue Jays beat Boston 4-3 on Saturday night to move into a tie with Baltimore for the top spot in the AL wild-card race.

The Blue Jays and Orioles each have 88 wins with one game to play, and Toronto owns the tie-breaker. Detroit and Seattle are also still in the hunt.

Toronto's' Melvin Upton Jr. blows a bubble after stealing second base during the fourth inning of a baseball game against the Boston Red Sox in Boston on Saturday. Associated Press/Michael Dwyer

With the loss, Boston fell one-half game behind Cleveland in the race for home-field advantage when their AL Division Series begins on Thursday.

One night after the Blue Jays blew a 3-1 lead and gave up the winning homer to the soon-to-be-retired David Ortiz, J.A. Happ seemed poised to pick up his 21st win of the season. But with Toronto leading 3-2 in the eighth, Mookie Betts doubled, took third on a double-play ball and then scored to tie it when closer Roberto Osuna (4-3) stopped his motion after starting to get into the stretch.

Osuna got Jackie Bradley Jr. to end the inning.

With struggling Red Sox closer Craig Kimbrel (2-6) pitching in the ninth, Michael Saunders drew a leadoff walk, and then pinch-runner Dalton Pompey took second on a sacrifice bunt, third on a wild pitch and scored on Carrera’s fly to left.

Kimbrel has losses in two of his last three appearances, issuing six walks while completing two innings. Since Sept. 22, his ERA has risen from 2.52 to 3.40.

The 21-year-old Osuna retired the Red Sox in order in the ninth.

Kevin Pillar drove in Toronto’s first three runs on a pair of RBI singles.

Betts had two hits and scored twice for Boston.

Ortiz walked and singled in three plate appearances before he was replaced in the fifth inning by a pinch-runner. The Red Sox designated hitter tipped his batting helmet to the crowd that stood and chanted “Papi!” for the second consecutive night.

Ortiz, 40, has announced this season will be his last. The Red Sox already extended his career by winning the AL East, but they are using his final regular season series to celebrate him.

Before Saturday’s game, Ortiz was joined on the field by other Boston sports stars, including Bruins legend Bobby Orr, NFL Hall of Famer Andre Tippett and the entire current Celtics’ roster. Several of the players asked Ortiz to sign their jerseys and pose for selfies with them.