SEATTLE — Pinch-hitter Kyle Schwarber hit a tiebreaking three-run double in the eighth inning and the Boston Red Sox beat the Seattle Mariners 8-4 on Tuesday night to keep pace in the competitive AL wild-card race.

Schwarber, out of the lineup in favor of Alex Verdugo, entered against reliever Drew Steckenrider with one out in the eighth and the bases loaded. His double to right ended a tense standoff with the Mariners, who beat the Red Sox 5-4 on Monday with the help of Schwarber’s fielding error.

Verdugo added a two-run home run in Boston’s next at-bat against Yohan Ramirez.

The victory kept the Red Sox percentage points behind the New York Yankees and Toronto Blue Jays for the AL’s two wild-card spots. Seattle dropped to three games back.

Boston starter Nathan Eovaldi, who struck out nine in the game, said the series feels like the postseason has already started.

“I feel like it has,” he said. “It’s very fun, you know what I mean? I feel like everyone is drained after the game.

“Everybody’s focusing, everybody’s battling out there, grinding,” he added. “It was a big team win for sure.”

Adam Ottavino (6-3) recorded the last out of the seventh inning for the win, which came after a stretch of six losses in eight games for the Red Sox. Eovaldi pitched five innings, leaving with the game tied at 2.

Xander Bogaerts tripled off the wall in right field to start the eighth inning, chasing reliever Joe Smith (2-4). Steckenrider entered tied with teammate Casey Sadler for the longest active scoreless streak in the AL at 18 1/3 innings, but he walked Rafael Devers to put runners at the corners. After a force out, he walked the bases loaded after starting with two strikes to pinch-hitter Travis Shaw.

Cora said he had no qualms about going to Schwarber, who has been struggling at the plate but hit before the game in both the indoor and outdoor batting cages.

“Those guys did an amazing job behind (Bogaerts),” Boston manager Alex Cora said. “Travis with the walk and then Kyle staying on a pitch and hitting a double. It was a great win. One that we needed obviously. We know where we are at and we know where they are at and everybody else. This was a good win.”

The outing was a rare failure by Seattle’s bullpen, one of the top performing units in the major leagues this year. Reliever Anthony Misiewicz also gave up a home run, allowing Seattle native Bobby Dalbec to tie it at 2 in the sixth after he inherited a one-run lead from starter Tyler Anderson.

Smith shouldered some of the blame for allowing Bogaerts’ long triple, putting Steckenrider in a tough spot.

“Those were some really good at-bats those guys threw up against one of our best,” Smith said.

It was Boston’s 42nd come-from-behind win this year.

Boston’s J.D. Martinez hit his 26th home run to open scoring in the fourth inning. The Mariners answered in the bottom of the inning with consecutive hits by Mitch Haniger and Kyle Seager. Hunter Renfroe then dropped Ty France’s high fly ball in right field to score Haniger and tie it at 1. Jake Fraley made it 2-1 later in the inning with a sacrifice fly.

HANIGER’S HUNDRED

Haniger scored his 100th run of the season in the fourth inning. He’s the first Mariners player to score that many since Robinson Cano had 107 in 2016.

TRAINER’S ROOM

Red Sox: The team reinstated LHP Martin Pérez from the COVID-19 injured list and returned RHP Kaleb Ort to Triple-A Worcester. … Manager Alex Cora said starting pitcher Chris Sale could return to the team as early as Friday and will start against the Baltimore Orioles if he’s activated in time. If not, he would start Saturday. Cora said the team sent an artificial mound to Sale’s home, and he’s been able to keep his arm in shape while sitting out. He last pitched Sept. 6. … OF Jarren Duran and INF Christian Arroyo, like Sale among nine players dealing with COVID-19 protocols, are at Worcester working out. If all goes well, they could soon return to the team as well.

Mariners: Fraley (right shoulder inflammation) was activated from the injured list and started in left field. Fraley has been out since Aug. 28. … RHP Justin Dunn (right shoulder inflammation) feels well enough to go on a rehab stint after two simulated games, manager Scott Servais said. The team has not yet scheduled the appearance, however. The starter will go to the Mariners’ bullpen if he’s able to return before the end of the season.

UP NEXT

Red Sox: RHP Tanner Houck (0-4, 3.54) looks for his first win as he finishes off the series with Seattle.

Mariners: Marco Gonzales (8-5, 4.03) has won his last seven decisions, a career-best stretch.