BOSTON — The first meeting in this renewed rivalry became a rout.

The Boston Red Sox scored nine runs in the sixth inning to break it open in a 14-1 romp over the New York Yankees on Tuesday night at Fenway Park.

Mookie Betts reached base five times, scoring five runs, capped with a grand slam in the sixth.

Boston has  won nine straight and continues to break the franchise record for best start, now at 9-1. The Yankees dropped to 5-6.

Chris Sale (1-0) finally got support and picked up his first win. He allowed one run – an Aaron Judge home run – over six innings, as his ERA sits at 1.06.

Yankees starter Luis Severino (2-1) came in with a 1.38 ERA, but the Red Sox got to him for five runs, knocking him out after five innings.

Ahead 5-1, the Red Sox pounced on New York’s bullpen, battering Tommy Kahne and Chasen Shreve in the sixth.

Betts was 4 for 4 with a walk, two doubles and his grand slam. He started the sixth-inning rally with a one-out double. After two walks, J.D. Martinez stroked a two-run double. The runs kept coming, and Betts came up again with the bases loaded and crushed a Shreve splitter over the wall in left-center. It was the third career grand slam for Betts.

Andrew Benintendi went 2 for 3 with two walks, a two-run triple and a double.

Hanley Ramirez knocked in three runs, going 2 for 2 with two RBI singles, a sacrifice fly and a walk.

Boston scored once in the first inning, and three times in the second, which was plenty for Sale.

Sale gave up eight hits but was never in big trouble. He struck out eight and walked none. Boston’s starting pitchers are now 6-0 with a 1.68 ERA.

Joe Kelly relieved Sale and pitched a scoreless seventh. Brian Johnson finished it with two scoreless innings.

NOTES: Yankees catcher Gary Sanchez was the designated hitter because of recent cramping in his calf muscles. Manager Aaron Boone said it was only a precaution … Dustin Pedroia, recovering from knee surgery, will head to Fort Myers next Tuesday to continue his rehab, although he is not ready to play in games … Red Sox Manager Alex Cora reported that reliever Tyler Thornburg, recovering from shoulder surgery, got his fastball up to 95 mph while working out in Florida. “The change-up is not there yet but to see his velocity there, that’s a good sign,” Cora said … Since Johnson pitched Tuesday, Hector Valzquez will likely get the Saturday start against the Orioles.

Kevin Thomas can be reached at 791-6411 or:

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Twitter: @ClearTheBases