Red Sox shortstop Xander Bogaerts, right, celebrates with Manager Alex Cora after an 8-6 win Sunday against the Baltimore Orioles at Fenway Park. Michael Dwyer/Associated Press

BOSTON — Kiké Hernández’s game-tying RBI single caromed off the second-base bag and into shallow center field, sparking a three-run, seventh-inning rally that carried the AL wild-card leading Boston Red Sox to an 8-6 victory over the Baltimore Orioles on Sunday and a sweep of their three-game series.

It was the fifth straight win for Boston, which leads Toronto by one game and the Yankees by 2½ in the playoff chase.

J.D. Martinez had a solo homer and Kevin Plawecki added a two-run single for the Red Sox.

“When it’s getting down to the end of the year and you don’t have a big lead and all the games matter, it gets to be a lot of fun,” Hernández said.

Trey Mancini had a three-run double for the Orioles, who have lost 12 of 13 against the Red Sox after sweeping a season-opening three-game series.

After giving up a two-run lead in the top of the seventh, Boston rallied against Conner Greene (1-1), getting the tying hit when Hernández’s grounder bounced off the bag, scoring José Iglesias.

“That’s exactly what I was trying to do. That’s how I drew it up,” Hernández said, smiling. “I was a little bit happy to get that hit and drive in that run.”

Hunter Renfroe followed with an RBI double high off the Green Monster and scored on Rafael Devers’ single.

“We got a little bit lucky with the ball off the bag,” Red Sox Manager Alex Cora said. “Then Hunter put on a huge swing. … Overall, another good win, obviously.”

The victory could be costly for the Red Sox, as reliever Garrett Whitlock had to leave the game because of right pectoral tightness. Whitlock, a Rule 5 pickup from the Yankees, has been a strong part of Boston’s bullpen.

“We’ll know more (Monday),” Cora said. “It’s too soon to know what’s going on.”

Hirokazu Sawamura (5-1) was credited with the victory despite giving up a two-run lead in the seventh. Garrett Richards got the final three outs for his third save.

The Red Sox jumped on starter Alexander Wells for three runs with two outs in the first. Bobby Dalbec got hit by a pitch with the bases loaded and Plawecki followed with his grounder to right.

Doubles by Alex Verdugo and Hernández in the second inning made it 4-0, but the Orioles got three runs in the third off Nathan Eovaldi.

Martinez’s shot into the first row of Monster seats in the bottom of the third made it 5-3, but the Orioles rallied in the seventh against Sawamura after Whitlock walked the leadoff batter. Sawamura issued two more walks, and all three runners scored on Mancini’s double down the left-field line.

Eovaldi struck out eight over five innings, allowing three runs on seven hits with one walk. The Red Sox have won his last six starts.

“The main focus is we’re winning these games,” Eovaldi said. “Things will even out (for me).”

Making his sixth major league start, the 24-year-old Wells gave up five runs in five innings.

KEEP THE KID IN

When asked why left-handed hitting slugger Kyle Schwarber wasn’t in the lineup, Cora didn’t hesitate to explain the decision.

“This is more about Bobby Dalbec than anything else,” he said. “Bobby has to play against every lefty.”

Dalbec, a right-handed hitter, has 12 homers and 36 RBI in his last 33 games, overcoming early-season struggles that saw him hitting only .174 with one homer and six RBI a month into the season.

CHASING HISTORY

Center fielder Cedric Mullins needs one more home run to become the first player in Orioles’ history with 30 homers and 30 stolen bases.

BEATING UP LEFTIES

It was the fifth straight game in which the Red Sox faced a left-handed starter, and they’ve scored seven or more runs in each game.

TRAINER’S ROOM

Orioles: Infielder Ramon Urías was scratched from the original starting lineup because of a right leg injury that’s been nagging him for about a month. “He tried to run this morning, just didn’t feel great,” Manager Brandon Hyde said. … Mancini and catcher Pedro Severino were back in the lineup after having Saturday off.