SEATTLE — Mookie Betts hit a solo shot as the Boston Red Sox used another ninth-inning home run to beat the Seattle Mariners 2-1 on Monday night.

Betts led off the top of the ninth inning with a tie-breaking solo home run, Boston’s third ninth-inning homer in two games, before closer Craig Kimbrel came on to earn his 18th save in his first game since July 6.

Seattle closer Steve Cishek (2-6) had another rough ninth inning after blowing a save opportunity at Wrigley Field the previous night. Cishek came on with the score tied 1-1 Monday and served up Betts’s 22nd home run of the season.

Boston third baseman Aaron Hill delivered his first home run in a Boston uniform with a one-out solo shot in the eighth. Hill’s homer off Seattle starter James Paxton tied the score 1-1.

Paxton allowed one run off four hits over eight innings, matching his longest outing of the season.

Robinson Cano had the Mariners’ first two hits of the game, including a one-out double in the seventh that led to the first run.

After teammate Nelson Cruz walked to put runners on first and second, Lee doubled to right-center, scoring Cano for a 1-0 lead. Boston starter Eduardo Rodriguez came out after that pitch, and reliever Robbie Ross Jr. got out of a bases-loaded jam with back-to-back strikeouts to end the threat.

Rodriguez allowed one run off three hits over 6 1/3 innings.

Seattle had a chance to score the go-ahead run in the bottom of the eighth, when a one-out single and a wild pitch left pinch hitter Norichika Aoki at second base before a groundout moved him to third. The Red Sox intentionally walked Cano to put runners on the corners for Mariners’ cleanup hitter Nelson Cruz, who struck out to end the threat.

Seattle (52-52) left eight runners on base, including seven over the final three innings. Kimbrel got the final out with runners on first and second base, striking out shortstop Shawn O’Malley to finish off the ninth.

The Red Sox (57-47) won back-to-back games for the first time since July 20-21 while moving within one game of American League East-leading Baltimore. Boston and Toronto are now tied for second place in the division and for the first wild-card spot.

Neither starter was giving up much in the early going.

Paxton retired the first seven batters before catcher Sandy Leon gave Boston its first hit with a one-out single in the third.

Rodriguez didn’t allow a hit until the fourth inning, having retired 10 of the first 11 batters before Cano broke up the early no-hit bid with a fourth-inning single.

Rodriguez helped himself with a nifty defensive play in the third, when he turned near disaster into an inning-ending double play. With one out and a runner on first base, O’Malley hit a hard liner back to the mound. Rodriguez somehow got his glove up to prevent the ball from hitting him in the face, resulting in a lineout before he threw to first to double up the runner.

NOTES: Boston bolstered its bullpen by acquiring veteran LHP Fernando Abad from Minnesota in exchange for minor league RHP Pat Light. RHP Joe Kelly, who started six games and made three relief appearances, was optioned to Triple-A Pawtucket. … The Red Sox activated closer RHP Craig Kimbrel from the 15-day disabled list. … Seattle, which had an open roster spot after dealing LHP Wade Miley to Baltimore on Sunday, recalled RHP Donn Roach from Triple-A Tacoma before Monday’s game. … Mariners LF Guillermo Heredia, who recently made his major league debut, was in the leadoff spot Monday. … Seattle’s scheduled Tuesday starter, LHP Wade LeBlanc, will be making his first appearance since July 23, when he pitched three innings of relief. He last started July 6. … The Mariners claimed INF Michael Freeman off waivers from Arizona and assigned him to Triple-A Tacoma. To make room on the 40-man roster, Seattle designated OF Patrick Kivlehan for assignment.