Aaron Judge of the Yankees strikes out during the ninth inning against...

Aaron Judge of the Yankees strikes out during the ninth inning against the Mariners at Yankee Stadium on Monday. Credit: Jim McIsaac

The Yankees were the surest thing in baseball.

Seven straight wins. Best record in the American League. An effective rotation pitching deep into games followed by an airtight bullpen and ironclad closer.

Aaron Judge and Juan Soto doing what they do.

And for eight innings Monday night, that winning formula again was working to perfection. Marcus Stroman dominated the AL West-leading Mariners into the eighth — retiring 15 straight during one stretch — and left to a standing ovation, even returning the favor by clapping his hands high above his head, then pounding his heart.

Alex Verdugo supplied three RBIs, Jon Berti tacked on another with his two-out single in the eighth and all Clay Holmes had to do was the bare minimum for a closer: protect a three-run lead by getting three outs.

Easy, right?

Holmes hadn’t surrendered an earned run in 20 appearances, the second-longest streak to start a season in franchise history, behind only Dellin Betances’ 26-game stretch in 2015. And even if the Mariners did dent him for a couple, Holmes still had that cushion.

Instead, catastrophe ensued. On most nights, the Yankees’ formula — the same script they’ve been following the past week or so — is going to produce the desired result. But not Monday, when Holmes was off by just enough to allow a few bad bounces to wreck his save opportunity and deliver a 5-4 victory to the Mariners before a shocked crowd of 37,590 in the Bronx.

Technically, Holmes allowed four hits, but only two left the infield. And here’s the exit velocity for the first three: 67.8 mph, 80.2 mph, 75.5 mph. Julio Rodriguez started the “rally” by beating out a 30-foot tapper to the left of the mound that Holmes couldn’t scramble for in time. After a one-out walk, Luke Raley then slapped a soft grounder up the middle that Gleyber Torres backhanded and made a wild, off-balance throw toward first that wound up in the Yankees’ dugout. Torres had no chance, but flung it anyway, costing Holmes a run and setting up Mitch Haniger’s RBI single that dropped in front of a charging Judge.

“Just kind of a do-or-die,” manager Aaron Boone said.

That was a very diplomatic way of putting it.

In the end, that play wound up killing Holmes and the Yankees. Another walk was followed by Dominic Canzone’s sacrifice fly and a single by Ty France that put the Mariners ahead, 5-4, for their first lead of the night. That also ended Holmes’ disastrous outing, without teeing up anything more than a few singles.

“That one’s on me,” Holmes said, taking responsibility anyway. “I felt like I made some good pitches, and definitely some balls found some holes, but I was ahead of a couple guys and ended up putting them on base . . . Things didn’t go our way there.”

As Boone and Stroman explained, “It’s baseball.” What else could they say?

With a three-run lead, any manager is handing the ball to his closer 99% of the time, barring any fatigue issues. From there, they can only watch. Holmes was as close to being a guarantee as any pitcher in the sport. Except for this one time.

“You can sit here and say it’s this, this and this, but Clay’s been unbelievable,” Stroman said. “I think Clay is the best closer in baseball. Think it was very weak contact. Essentially if they hit the ball harder on some of those plays we probably wouldn’t be in this situation. So I think you just have to honestly understand that.

“Clay is going to continue to be incredible for us. Not even a slight worry there. But that’s how baseball shakes out sometimes. Just didn’t go your way.”

It was especially tough to swallow for Stroman, who baffled the Mariners all night (one walk, 6 Ks) and served up his only run on Canzone’s one-out homer in the eighth — his last batter. Because of Holmes, it was the first time in eight starts (7-0) the rotation didn’t come away with a victory, yet they still have an 0.86 ERA over that stretch. They also have thrown at least six innings in those eight starts, allowing a total of six runs, making just the second time that’s happened in franchise history (1932 was the other).

Monday night was supposed to be another feel-good win for the Yankees, to add on top of the rapidly-growing pile. Seeing Stroman soak up that mutual admiration from the Bronx fans deserved a happier ending. And there was no reason to expect otherwise.

“That’s why we play the game,” Stroman said of the applause. “Being born here and coming out of the game to a standing ovation means the world to me. Just trying to reciprocate the love from the crowd right back to them because they don’t know how much that means to me.”

Not long after, Holmes was treated to a much different reception coming off the mound in the ninth. For once, the Yankees’ formula blew up in their face. If it’s any consolation, better May than October.

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