Mookie Betts capped a 13-pitch, fourth-inning at-bat against Toronto starter J.A. Happ with a go-ahead grand slam to power the host Boston Red Sox past the Blue Jays 6-4 Thursday night in the opener of a four-game series at Fenway Park.

Betts finished with five RBIs for the Red Sox, who established a season high with their 10th consecutive victory. Boston matched its previous high of nine straight with a 4-2 win Wednesday to sweep the Texas Rangers.

Boston starter David Price (10-6) bounced back from a pair of subpar starts to toss 6 2/3 innings of three-run ball. Price struck out eight, gave up six hits and walked none to become Boston's fourth 10-game winner this year.

Teoscar Hernandez hit a two-run homer, Kendrys Morales slugged a solo shot and Justin Smoak ripped an RBI double for Toronto, which couldn't avoid its fourth loss in five games.

Happ (10-6) gave up five runs, all unearned, on five hits and a walk with six strikeouts over 3 2/3 innings.

The Blue Jays fell to 2-8 against the Red Sox this season. Boston moved 37 games over .500 this season, a feat they last achieved in 1949.

Hernandez took Price deep in the first for his 14th homer of the year, putting Toronto up 2-0.

Boston scored five runs in the fourth, forcing Happ to throw 46 pitches.

With one out, Brock Holt rolled a potential double-play ball to shortstop, but Blue Jays second baseman Devon Travis' foot came off the bag on the play. Both runners were ruled safe after a Red Sox challenge.

Eduardo Nunez singled to load the bases, and Sandy Leon made it 2-1 with a fielder's choice grounder to shortstop that got Holt at third. Jackie Bradley Jr. walked to reload the bases, setting up Betts' lengthy at-bat that ended with his 23rd homer.

Morales hit his 11th homer in the seventh, but Betts answered with an RBI single in the home half of the inning. Smoak's two-bagger in the eighth brought the Blue Jays within two, but Boston closer Craig Kimbrel tossed a scoreless ninth for his 29th save.

Toronto southpaw Ryan Borucki (0-1, 2.25 ERA) opposes Boston righty Rick Porcello (11-3, 3.58) on Friday night.

--Field Level Media