Cincinnati’s Spencer Steer crosses home plate and celebrates with Kevin Newman after his two-run home run against the Boston Red Sox during the seventh inning Wednesday in Boston. At right is Red Sox catcher Connor Wong. Charles Krupa/Associated Press

BOSTON — Spencer Steer hit a two-run homer to break a seventh-inning tie and the Cincinnati Reds took advantage of Rafael Devers’ throwing error to come from behind and beat the Boston Red Sox 5-4 on Wednesday night.

“You give the opposition more than 27 outs, most of the time they’re going to score. They’re going to make you pay,” said Red Sox manager Alex Cora, who lamented his team’s poor defense before the game and then watched it hurt them again. “That play we have to make, we didn’t. And it opened the gates for them.”

Kevin Newman, Matt McLain and Nick Senzel had two hits apiece for the Reds, who have won five in a row, taking the first two of their three games in Boston to beat the Red Sox in a series for the first time since the 1975 World Series.

Ian Gibaut (5-1) pitched one inning of perfect relief for Cincinnati, which trailed 2-0 and 3-1 before scoring one in the sixth and three unearned runs off Josh Winckowski (2-1) in the seventh to take a 5-3 lead. With closer Alexis Díaz needing a break after finishing the previous three games, Buck Farmer pitched the ninth, retiring Devers on a deep fly to center to end it.

“It’s an honor for them to be able to trust me like that,” said Farmer, who earned his first save of the season and the third of his 10-year career. “It’s kind of a feeling that I can’t explain. But I thank them and was happy to get it done.”

Masataka Yoshida curled a home run around the Pesky Pole and Emmanuel Valdez landed one on the shelf atop the Green Monster for Boston. Devers and Jarren Duran had RBI doubles.

Boston led 3-1 after five and 3-2 through six before Luke Maile led off the seventh with a hard chopper to third base and Devers one-hopped the throw past first baseman Justin Turner. It was Devers’ fifth error of the season, and the 35th for the team in 55 games.

Newman and McLain singled to load the bases, then one run scored on Jonathan India’s double play groundout. Steer cleared the Green Monster with his eighth homer of the year to make it 5-3.

“That’s always huge,” Farmer said. “When you can tack on — and not only that, take the lead — from it and capitalize on that, it’s a momentum shift. And then from then putting up zeros is huge.”

The Red Sox loaded the bases in the bottom half, but Alex Young got Turner to ground out to short to end the threat. Duran’s double made it 5-4 in the eighth, but Lucas Sims got Raimel Tapia on a lineout to center and then struck out Valdez to strand Duran at second.

FOR STARTERS

James Paxton allowed one run on four hits and a walk, striking out eight in five innings for Boston. He left with a 3-1 lead. Luke Weaver gave up three runs on seven hits, striking out five in 5 2/3 innings; he averted the loss when the Reds scored one in the sixth and one in the seventh to tie it.

TRAINER’S ROOM

Newman got hit by a pitch in the ninth inning with a high fastball that was headed for his face before he got his left arm in front of it. Reds manager David Bell said he would be OK.

UP NEXT

The teams complete their three-game series on Thursday, with Red Sox LHP Chris Sale (5-2) facing Reds RHP Hunter Greene (1-4).