Giancarlo Stanton, left, celebrates with Joey Gallo, right, and Aaron Judge after hitting a two-run homer in the eighth inning Sunday night, propelling the Yankees to a 6-3 win and a series sweep against the Red Sox at Fenway Park. Michael Dwyer/Associated Press

BOSTON — Yankees Manager Aaron Boone watched two of his Gold Glove fielders drop easy popups to hand the Red Sox the lead.

Then Boston fumbled a pair of foul balls with Aaron Judge at the plate, twice giving the slugger new life before his two-run double propelled New York to a 6-3 victory on Sunday night and a series sweep that flipped the lead in the AL wild-card race.

“It’s a little bit stunning, right? You can’t make that stuff up,” Boone said. “It’s not something you’re going to see very often, two popups get dropped by really good defenders. It’s part of the ride right now.”

After Judge turned a 3-2 deficit into a 4-3 lead, Giancarlo Stanton hit a two-run homer over the Green Monster and out of the ballpark to seal the Yankees’ sixth straight win. Stanton, who won Saturday’s game with an eighth-inning grand slam, homered in all three games and drove in 10 runs during the series.

Mickey Mantle is the only other Yankee with 10 RBI in a three-game series versus the Red Sox; Joe DiMaggio is the only other one to homer in each game of a three-game series against them.

“It’s a big time right now, so I’ve just got to make sure I’m the most prepared,” Stanton said. “You can’t be scared of those moments, or they’ll sneak up on you real quick.”

The Yankees, who arrived in Boston trailing the Red Sox by two games, leave with a one-game lead in the race to host the Oct. 5 AL wild-card game. Boston remains in playoff position, one game ahead of Toronto for the second wild-card spot.

“It’s not what we wanted coming into the series,” Red Sox Manager Alex Cora said. “We didn’t get the job done. It’s that simple.”

After Boston took a 3-2 lead in the seventh on two Yankee errors – a pair of dropped popups – New York put runners on second and third with one out before Judge hit a foul ball that rookie first baseman Bobby Dalbec short-armed as he approached the Red Sox dugout. The Red Sox had a second chance to retire Judge when he tipped a 1-2 pitch, but catcher Christian Vazquez was ruled to have dropped it. (Replays showed that Vázquez lost the ball on the transition to his throwing hand.)

“I felt like a cat,” Judge said. “I felt like I’ve got nine lives out there.”

Judge then hit a line drive to left-center to make it 4-3.

“You can’t give that man too many extra chances,” Stanton said. “It was just a tremendous at-bat for him to keep pushing, keep fouling pitches off and waiting to get one he could drive into the gap.”

Boone said Judge dislocated his pinky sliding headfirst into second base. They were able to pop it back into place and he finished the game.

“Not too concerned with it,” Judge said. “I don’t need it to hit, so I think we’ll be in good shape.”

Chad Green (10-7) earned the win despite blowing a 2-1 lead in the seventh when DJ LeMahieu and Joey Gallo dropped easy popups, allowing the go-ahead run to score. In all, Green allowed two hits in 1 2/3 innings, striking out two.

Aroldis Chapman pitched the ninth to earn his 30th save.

Garrett Richards (7-8) pitched a perfect seventh but walked two and gave up Anthony Rizzo’s double in the eighth before Adam Ottavino relieved him and allowed Judge’s double.

New York led 2-1 when José Iglesias singled to lead off the seventh and took second on Alex Verdugo’s bunt single. Joely Rodríguez’s wild pitch moved the runners up, and Christian Vázquez hit a sacrifice fly to tie it.

Chad Green struck out Kiké Hernández, but when pinch-hitter Kyle Schwarber popped up the first pitch he saw in front of the Yankees dugout, LeMahieu flubbed it. Another seemingly easy popup clanged off Gallo’s glove in left-center, allowing the go-ahead run to score.

NO SMOKE, NO FIRE

The game was delayed four minutes with two outs in the top of the fourth inning when the fire alarm went off in Fenway Park. The umpires called time, but the teams remained on the field. The Red Sox said the alarm was caused by a faulty sprinkler head.

When the game resumed, Stanton buzzed pitcher Eduardo Rodríguez’s head with a line drive that ricocheted off second base into center for a single.

TRAINER’S ROOM

Red Sox: Placed left-hander Josh Taylor on the injured list (retroactive to Sept. 23) because of a low back strain. Right-hander Eduard Bazardo was recalled from Triple-A Worcester to take his spot on the roster.