Dylan Moore gave the Mariners a lead they never surrendered by homering on a pitch that Clarke Schmidt believes Moore saw coming.

The Yankees’ 6-3 loss to Seattle in front of 31,257 in The Bronx on Tuesday probably could be blamed more on their inability to hit opposing starter Bryan Woo; or maybe on the five total hits they collected; or perhaps on some duds from Aaron Boone’s bullpen.

But the moment that will be remembered from the Yankees (33-17) dropping a second straight game for the first time since April 30 arrived in a third inning that the Yankees have studied and probably will study again.

Schmidt was rolling, having retired the first seven Mariners batters he saw, including striking out the side in the second inning, before Josh Rojas doubled down the first-base line.

What followed was a long, seven-pitch at-bat that Schmidt believes included Rojas, from second base, picking up a tell from the pitcher and subtly relaying it to Moore, who was at the plate.

Schmidt located well with a full-count cutter that was dotted on the outside of the plate, but Moore turned on it and smacked the offering 386 feet to left field for a two-run home run that put Seattle in front to stay.

“I think there was a little bit of relaying the signs a little bit at second [base],” Schmidt said after allowing just those two runs on four hits in five innings. “It was a quality pitch for sure. Obviously tipping’s a part of this game, and it’s a factor.”

Schmidt did not divulge what act, in his delivery or mannerisms, he believed led to the Mariners detecting what pitch was coming.

But the fifth-year righty said he pored over the video in between innings and made adjustments that he believes fixed the issue.

“Everybody has things that they do that you might pattern in certain ways with the way you come set or whatever it may be,” said Schmidt, who snapped a streak of eight consecutive quality starts by Yankees starters. “Maybe in years past I had a different tip, and now it’s another tip. It’s just constantly paying attention and making sure you’re staying on top of small things like that.

“Obviously, it can be a difference in a game.”

Schmidt commended Seattle for being “well-prepared,” and the AL West leaders have sent a little message in taking the first two games of a four-game series with strong pitching and, at least on Tuesday, an impressive display of power. The Mariners blasted four home runs — two by Moore — to pull away.

The Yankees could do nothing against Woo, a 24-year-old righty who threw six scoreless innings and allowed just two hits without a walk.

Three games into his season, Woo’s ERA is 0.57.

“He was tough and kind of had his way and was real pitch-efficient,” Boone said of Woo, who is still building up and was pulled after 77 pitches. “He beat us tonight.”

The Mariners had opened up a four-run lead until the Yankees cracked through in the seventh inning. A walk and hit by pitch set the table for Gleyber Torres, who drilled a three-run homer that brought them within one.

But Seattle responded with a Luke Raley homer in the eighth inning that rudely welcomed recent call-up (and postgame send-down) Clayton Andrews before Moore launched his second homer of the night in the ninth, this one against Nick Burdi.

The Yankees brought up Juan Soto and Aaron Judge as the potential tying runs in the eighth, but both were retired. Jose Trevino and Torres reached against closer Andres Munoz in the ninth, but potential-tying-run Oswaldo Cabrera struck out to end it.

If the Yankees indeed were upended because the Mariners decoded something in Schmidt’s delivery, the Yankees are not complaining. Schmidt called it “100 percent” fair game.

“If I’m tipping pitches, it’s a credit to them for being able to find it,” said Schmidt, who had gone 17 ²/₃ innings without allowing a run before serving up that home run. “And especially to Moore for being able to capitalize on a mistake.”