NEW YORK — Add one more item into the New York Yankees’ ever-expanding folder of “Things Gone Wrong.’’

A controversial play at the plate ultimately went against the Yankees on Sunday afternoon, helping the Boston Red Sox to a 6-5 victory and sending Aaron Boone’s club to its eighth straight loss.

It’s the longest Yankees losing streak since August 1995, and Sunday’s defeat left the Yankees a whopping nine games out of a wild card spot with 38 games to play.

"We've got to be unbelievable the rest of the way,'' said Boone. "But you can't even get big picture about it. You've just got to tackle the next day.

“Another one that stings,’’ said Boone. “Especially with what we’re going through. But we’re not allowed for it to be deflating.

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“We’ve got to dig ourselves out and play better and start winning games.’’

IKF: "I didn't think they had enough evidence''

Attempting to score on Anthony Volpe’s two-out single, with the score tied 5-5 in the eighth inning, Isiah Kiner-Falefa was initially ruled safe.

But the call was overturned on replay review, and it withstood another challenge when the Yankees inquired whether Boston catcher Connor Wong had illegally blocked the plate.

Had the call been upheld, the Yankees would have had their first lead in nearly a week.

As it stands, the Yankees’ last lead of any kind was the second inning of last Monday’s 11-3 loss in Atlanta.

“I didn’t think they had enough (evidence) to overturn it,’’ said IKF. "On the big (scoreboard replay) screen, I definitely didn't see anything that was clear that he tagged me. I thought I got in there.''

Controversial play goes against Yankees

Here’s how the play developed:

Running from first base with two out, Kiner-Falefa was waved home by third base coach Luis Rojas as left fielder Rob Refsynder slipped on the outfield turf fielding Volpe’s base hit off Chris Martin.

The Yankee Stadium outfield grass has been soft and spongy all week, possibly due to temporary stands constructed for the Jonas Brothers concerts last weekend.

Refsnyder scrambled up and relayed to Trevor Story, whose throw beat IKF, who made a straight slide to the plate.

Umpire Junior Valentine called IKF safe, but the Red Sox immediately challenged the call, followed by a lengthy review.

From his vantage, Boone wasn’t sure whether IFK was safe or out in real time.

“I’m sure they have evidence’’ confirming the out call, said Boone. In a statement by the MLB replay supervisor, it was “definitively determined that the catcher tagged out the runner prior to the runner touching home plate.’’

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MLB's explanation on call overturned vs. Yankees

Also, the Yankees’ challenge of Wong blocking Kiner-Falefa was dismissed.

“I didn’t feel like I had a lane,’’ said IKF, but the MLB replay supervisor ruled there was “definitely…no violation of the Home Plate Collision Rule.

“The catcher’s initial setup was legal, and he moved in reaction to the trajectory and hop of the throw.’’

Boone checked with the league after the game but did not dispute the ruling.

In real time, watching such plays at the plate develop seem “fine’’ to Boone. “But some of the (replay) calls they’ve made on blocks, it gets a little gray there.

“They said (Wong) set up properly, which we agree with, in fair territory. They said he moved late enough to catch the ball where it took him, that was the explanation.’’

Red Sox dominance over the Yankees

Clay Holmes gave up the go-ahead run in the top of the ninth, and Kenley Jansen struck out both Aaron Judge and Gleyber Torres with the tying run on second before getting Ben Rortvedt to fly out.

In completing a three-game sweep at Yankee Stadium, the fourth-place Red Sox (66-58) boosted their record against the Yankees (60-64) this year to 8-1.

"Yeah, they've kicked our (butts),'' Boone said evenly.

Boston won the first two games this weekend by a combined 16-4 score.

Sunday, the Sox had big contributions by Rafael Devers (homer, double, three runs scored) and Justin Turner, with a three-run homer off Michael King and a go-ahead double off Holmes.

"We've played a handful of competitive games that have come down to the end,'' Boone said. "We just haven't been good enough.''