BOSTON — Doug Fister took a shutout into the eighth inning, rookie Rafael Devers went 4 for 4 and drove in a run and the Boston Red Sox beat the Cleveland Indians 6-2 on Monday night.

Mookie Betts stopped his mini-slump by driving in three runs with two singles, and Eduardo Nunez added three hits and two RBIs for the Red Sox, who won for the third time in nine games.

Bradley Zimmer hit a two-run homer for AL Central-leading Cleveland, which lost its second straight after a season-high nine-game winning streak.

Fister (1-5), claimed off waivers from the Los Angeles Angels on June 23, was pulled after giving up Zimmer’s homer with two outs in the eighth. He allowed two runs and five hits, walking two and striking out five.

Brandon Workman got the final four outs.

Mike Clevinger (5-4) gave up five runs on seven hits in three innings.

Betts, the runner-up for last season’s AL MVP award, flied out with the bases loaded to end a loss Sunday and was 3 for his last 27 without an RBI.

Before the game, both clubs beat the non-waiver trade deadline and added bullpen help. The Red Sox picked up right-hander Addison Reed from the Mets for three 22-year-old right-handed pitching prospects.

The Indians acquired righty Joe Smith from Toronto for two minor leaguers.

Betts’ two-run single sparked a three-run second. He scored on Nunez’s double.

In the fourth, Betts added another RBI single, and Nunez added a run-scoring single.

Devers’ RBI single made it 6-0 in the seventh.

Dustin Pedroia missed his third straight game because of a sore left knee. Manager John Farrell said the improvement has been “slight” and he’s scheduled to see a specialist Tuesday.

Dave Dombrowski said: “The problem with Dustin is he has a bad knee. He’s had it for years and he’s had to have to deal with that.”