Mookie Betts homered to lead off the ninth inning, Kimbrel got his 18th save in his return from the disabled list and the Red Sox beat James Paxton and the Seattle Mariners 2-1 on Monday night.

Mookie Betts touches home plate on his game-winning home run in the ninth inning Monday night in Seattle. Associated Press/Elaine Thompson

Kimbrel made his first appearance since having surgery to repair a medial meniscus tear in his left knee. He allowed a walk, and Kyle Seager reached on a third-strike wild pitch, but Kimbrel got two other strikeouts to end it.

“As much as we talked before the game about Kimbrel and giving him a little breathing room, that one-run margin wasn’t a heck of a lot,” Farrell said. “He was very good. It looked like he hadn’t missed any time.”

“That’s my job,” Kimbrel said. “I like save situations. It worked out nice.”

Paxton held Boston to a run and four hits over eight innings before Betts hit his 22nd homer off closer Steve Cishek (2-6), who blew a three-run lead in the ninth inning Sunday against Chicago.

Seattle may turn over closing duties to hard-throwing rookie right-hander Edwin Diaz.

“We’ll talk about it,” Servais said. “We’ll probably take the gas off a little bit and try to get (Cishek) in some better spots, and maybe not when the game is on the line all the time, and get it back going again.”

Aaron Hill homered off Paxton in the eighth to tie the game 1-1. It was the second straight ninth-inning comeback for Boston, which beat the Angels 5-3 with five two-out runs in their final at-bat Sunday.

“You have to play 27 outs to beat us,” Betts said. “We’re starting to see that more and more now.”

Junichi Tazawa (2-1) got the win with a scoreless eighth after Eduardo Rodriguez held Seattle to a run and three hits over 6 1/3 innings.

Rodriguez held the Mariners to three baserunners in the first six innings, and only one of his first 19 outs even left the infield.

Paxton retired the first seven batters until Sandy Leon’s one-out single in the third. Hanley Ramirez singled in the fifth and Betts was the first player to reach second with a two-out double in the sixth. All failed to advance.

Dae-Ho Lee’s run-scoring double with one out in the seventh chased Rodriguez, who allowed three hits, two walks and six strikeouts. Robbie Ross Jr. took over and hit Seager with a pitch to load the bases with one out. He then struck out Franklin Gutierrez and Chris Iannetta.

Paxton had six strikeouts and no walks.

KID COMING

The Red Sox will promote prospect Andrew Benintendi from Double-A to the majors before Tuesday night’s game. The outfielder is one of the top prospects in baseball, hitting .312 with nine homers, 76 RBIs and 16 stolen bases this season between Class A Salem and Portland.

PITCH FOR PITCH

The Red Sox added Kimbrel off the injured list, just three weeks after his July 11 surgery. To make room, the club optioned RHP Joe Kelly to Triple-A Pawtucket. The Mariners also added a pitcher, RHP Donn Roach from Triple-A Tacoma. He is likely a temporary fix for the team’s depleted staff.

MIRANDA THURSDAY?

The Mariners have not announced a pitcher for Thursday’s game, and manager Scott Servais said “there’s a possibility” that lefty Ariel Miranda could pitch. Miranda was acquired from Baltimore for lefty Wade Miley on Sunday.

TRAINER’S ROOM

Mariners: RHP Taijuan Walker (right foot tendinitis) had a rehab start for Triple-A Tacoma on Monday. … SS Ketel Marte (mono), on the DL since July 20, is nearly back to his playing weight. … RHP Nick Vincent (back strain) will throw a simulated game Tuesday, with Marte facing him. If that goes well, both likely will be ready for rehab assignments.

UP NEXT

Red Sox: LHP David Price (9-7, 4.26) has lost his past three starts, although he was beaten 2-1 Thursday by the Angels, working eight innings and allowing no runs and seven hits.

Mariners: LHP Wade LeBlanc (1-0, 4.26) was acquired in a trade with Toronto June 21.