NEW YORK -- Trying to hang on in the American League Wild Card race, the Red Sox seemed on their way to a big victory, riding an emergency start from No. 13 prospect Richard Fitts in place of Tanner Houck and two-run homers by Masataka Yoshida and Trevor Story.

But it all fell apart in the bottom of the seventh inning, when the Yankees took advantage of wildness by Red Sox relievers Zack Kelly and Cam Booser and rode Aaron Judge’s grand slam to a 5-4 victory.

Considering the stakes, it was one of the most crushing defeats of the season for Boston, and one that might be hard to recover from.

The one positive is that the Twins are also slumping and lost to the Reds on Friday, meaning the Red Sox stayed 4 1/2 games back for the third AL Wild Card spot with 14 games left in the season. Minnesota comes to Fenway for a three-game series next weekend.

However, the Tigers are hot and trail the Twins by just 2 1/2 games.

“It's up there with some of them,” Red Sox manager Alex Cora said of the sting of Friday’s defeat. “But then you look up and you're like, ‘Man, how [are we still in this]?’ I mean, I hate to say it, but it's still there for us. We’ve just got to win a few games and make it interesting next week.”

The hardest part of Friday’s game for the Red Sox was how quickly it fell apart. Leading 4-0 heading into that fateful bottom of the seventh, Cora turned to Kelly, who walked No. 8 and 9 hitters Anthony Volpe and Alex Verdugo. Kelly was ahead in the count, 0-2, to Verdugo before losing him in the seven-pitch at-bat.

After an RBI single by Gleyber Torres, Cora went to Booser to face Juan Soto.

Booser walked Soto on four pitches, bringing Judge to the plate with the bases loaded. The superstar slugger did not let the chance go to waste, ripping a 2-0, center-cut fastball over the wall in left for his 52nd homer but first since Aug. 25.

“I think the team did everything they needed to do,” said Booser. “I think this is solely on me. Didn’t do my job, didn’t get ahead, didn’t throw strikes, and put Judge in a position to look for one pitch, and yeah, tonight’s on me, not on the team.”

Kelly disagreed.

“I put Boos in that situation,” said Kelly. “Tough situation for anybody, and he’s been a workhorse for us this year. That situation never should have happened in the first place. I take ownership of that and don’t blame anybody but myself.”

Bullpen meltdowns have been a recurring theme for the Red Sox since the All-Star break.

“We’ve got to throw strikes,” said Cora. “It’s a 4-0 lead with the eighth and ninth hitter up. We ran into the corner with the best hitter in the American League. He did what he's been doing the whole season. Just a tough one, because, you know, if you throw strikes and they get hits, it's [OK]. But we didn't do that.”

The night started with such promise for the Red Sox as Fitts worked out of a bases-loaded jam in the first and settled in to fire five scoreless innings in his second Major League start. The former Yankees prospect was acquired along with Greg Weissert and Minor Leaguer Nicholas Judice nine months ago. Houck was scratched an hour before the game started due to right shoulder fatigue.

“It was a pretty unreal night,” said Fitts. “I was excited to be here. It's a quick turnaround to find out when I was starting. But I welcomed the challenge. It's pretty cool to have that here in Yankee Stadium.”

Yoshida’s two-run rocket to right-center against Clarke Schmidt put Boston up, 2-0, in the sixth. And Story, who came back from a five-month absence, lifted a two-run shot to right-center in the seventh.

But a four-run cushion wasn’t enough on a night when Boston’s bullpen ERA since the All-Star break swelled to 6.37, 30th in the Majors over that span.

“It's a tough one, no getting around it,” said Story. “Masa got to Schmidt there early, and then [my] home run later, and it’s just tough, man. Tough game. That kind of stuff can happen in the big leagues. We always have our guys’ backs, though. Boos and Kelly. That's a tough one for them, but we always have their backs.”