Martinez, who broke out of an 0-for-20 slump with three hits, drove a 2-1 pitch into the seats in right field. Martinez also singled in the first and sixth after being given the night off Friday.
Jarren Duran began the 10th inning as the runner on second base and moved to third on Kyle Schwarber’s single to left off Wittgren (2-7) before Martinez delivered.
“I told myself to relax, put the ball in the air and get the run in," Martinez said. “I was fortunate to be able to flush it and get it out.”
The homer was the 24th of the season for Martinez.
“He's a huge stud at the plate,” Red Sox starter Nathan Eovaldi said. “He's been scuffling here a little but you get him back swinging the way we know he can, like he was at the beginning of the season, we're going to be even more more deadly out there.”
Boston's Adam Ottavino came on in the 10th with the bases loaded and one out. He struck out Austin Hedges before Óscar Mercado’s single cut the lead to two runs. Ottavino retired Andrés Giménez on a groundout for his 10th save and second of the series.
Garrett Whitlock (6-2) pitched around a one-out single in the ninth.
Boston, which holds the AL's second wild-card spot, used Jonathan Araúz’s three-run homer in the eighth inning to beat the Indians 4-3 on Friday.
The Indians stranded 13 baserunners and were 2 for 13 with runners in scoring position.
“We had our chances,” interim manager DeMarlo Hale said. “There are some things we can do better, but we have to put this behind us. That's a good team over there.”
Eovaldi allowed two runs and struck out six, throwing 97 pitches in 5 1/3 innings. The right-hander gave up Franmil Reyes’ solo homer in the second.
Cal Quantrill gave up two runs, one earned, in seven innings. Boston had runners on second and third with one out in the seventh, but Araúz popped out and Duran flied out. Quantrill, who allowed Schwarber’s solo homer in the first, struck out six.
Schwarber homered to center with one out in the first, his 27th of the season. Martinez singled and scored when left fielder Daniel Johnson booted Xanxder Bogaerts’ double into the corner.
Reyes led off the second with a home run into the left field bleachers, his 24th. Bradley tied the game with an RBI double. Bradley was activated from the 10-day injured list after struggling reliever James Karinchak was optioned to Triple-A Columbus. Bradley injured his knee Aug. 6.
Plate umpire Ron Kulpa remained in the game after being hit in the mask by Christian Vázquez’s foul tip in the seventh. Kulpa was checked by an Indians trainer and other members of the umpiring crew.
Red Sox manager Alex Cora is keeping up on the conditions of infielder Kiké Hernández, who has tested positive for COVID-19, and second baseman Christian Arroyo, who had close contact with Hernández.
“I’m always checking on them,” Cora said before the game. “We’ll keep hoping that everything goes well in the upcoming days.”
SORRY ABOUT THAT
Hedges accidentally hit Duran on the helmet when he threw a ball back to Quantrill in the third inning. The errant toss bounced off Duran’s helmet and rolled to the third base line. Hedges patted Duran, who took the pitch for a strike, on the leg. No one was on base at the time.
Red Sox: OF Danny Santana (strained left groin) is scheduled to play nine innings in a rehab game for Double-A Portland on Sunday.
Indians: RHP Aaron Civale (sprained right middle finger) could return to Cleveland’s rotation soon. He hit 92 mph while throwing 4 1/3 scoreless innings during a rehab assignment at Class A Lake County on Friday. ... RHP Shane Bieber (strained shoulder) is scheduled for a bullpen session Aug. 31.
RED SOX: RHP Tanner Houck (0-3, 3.43) allowed three run in 4 2/3 innings in a no-decision in his last start against Texas on Aug 24.
Indians: RHP Eli Morgan (2-6, 5.98) got the loss against the Rangers in his last start, allowing four runs in 4 1/3 innings.
World Series 2021: The best hitting and pitching tools in the Astros-Braves Fall Classic
Is Yordan Alvarez the biggest bat in the World Series? With Charlie Morton out, who's got the nastiest curveball? Kiley McDaniel has the definitive list.
World Series 2021: Dusty Baker makes these Houston Astros about so much more than a scandal
Hate Houston if you want. But as one of Dusty Baker's former players, I know there's so much to love about its manager.
Atlanta Braves' Game 2 starter Max Fried says he's 'not against' pitching Game 5 on short rest
Atlanta's Game 2 starter said, "We'll see how I feel over the next couple days," as the Braves look at pitching solutions in the wake of Charlie Morton's broken leg.
Jose Altuve breaks out to help Houston Astros tie up World Series against Atlanta Braves
Jose Altuve scored the first run of the night, then tallied the final one on a home run that moved him into a tie for second in postseason homers, as the Astros evened the World Series against the Braves.
How the Astros were able to rebound in Game 2
Eduardo Perez and Tim Kurkjian detail how Jose Urquidy, Jose Altuve and the Astros were able to get the win in Game 2.
Astros bounce back with Game 2 win to even series
The Astros score four in the second, and Jose Altuve adds a home run to level the series at one game apiece.