BOSTON — On Saturday, Jasson Domínguez contributed to the Yankees’ scoreboard by driving in their first run in the top of the seventh inning. Later, his ninth-inning double put them in position to potentially equalize against the Red Sox.

But it was his brutal mental blunder on the bases in that seventh inning that really stood out in a 4-3 loss.

With two out in the inning, Domínguez was at second, Austin Wells at first and the Yankees had scored twice.

But Domínguez inexplicably was caught between second and third on a pitch that Trent Grisham missed for the second strike of the at-bat.

Catcher Carlos Narvaez spotted Domínguez caught in limbo, quickly throwing to shortstop Trevor Story. Story then relayed the ball to Marcelo Mayer at third base, where Domínguez was tagged out, ending their scoring opportunity.

Domínguez owned up to the mistake, saying he thought Grisham had struck out on the pitch, which would have been the third out.

Instead, it was an ugly miscue.

“I thought he had two strikes, but I have nothing to say, no excuses,” Domínguez said. “I made a mistake.”

Upon learning that manager Aaron Boone expressed confidence he wouldn’t repeat the error, Domínguez responded, “Absolutely, after having this experience, I will definitely be more vigilant.”

The play was so unusual that Boston manager Alex Cora wasn’t even sure what happened after the game, wondering what led Domínguez to wander so far off the bag.

Regardless, he was pleased with the result — especially with how it impacted the remainder of the game.

“That’s a huge play in that situation,’’ Cora said. “Then we can send [Justin] Wilson back for Grisham [in the eighth].”

The lefty retired Grisham to start the eighth and retired the side in order.

Boone said he spoke with Domínguez afterward and reminded him the importance of staying aware of the game situation.

It spoiled what was somewhat of a productive night for the slumping rookie.

Domínguez entered Saturday hitless in his previous nine plate appearances and in the midst of a funk that dates back more than a month, but has been especially rough since May 25.

He was 8-for-41 with one extra-base hit and 17 strikeouts in 46 plate appearances in his previous 12 games and hadn’t had an RBI in a 15-game stretch.

Domínguez lined out in the second and flied to left in the fifth before the run-scoring single in the seventh.

After being erased on the basepaths later in the seventh, Domínguez extended the failed rally in the ninth with the double, but was stranded there when Wells lined out to center to end the game.