Giancarlo Stanton has 18 career postseason home runs as a Yankee.

And he thought he had hit No. 19 to lead off the bottom of the second inning against the Red Sox in Game 3 of the Wild Card Series.

Stanton bombed a pitch of Connelly Early to straight away center field that initially looked like a homer that would give the Yankees a 1-0 lead.

Stanton let out an audible cuss word in celebration and then changed his facial expression to panic, and uttered another curse word, when the ball hit the wall. After taking a leisurely 7.51 seconds to go from home to first, Stanton had to turn on the jets and hustle into second base in 3.82 seconds, per ESPN.

Luckily, it did not cost the Yankees, who won 4-0. Stanton called it a “bonehead play” after the game.

“Kids at home. Don’t do that. Future opponents. Please do that. It won’t happen again,” he told reporters.

The Yankees then left Stanton stranded at second base as the game remained scoreless through two innings.

The ball would have been a home run in half of Major League Baseball’s parks.

Meantime, both rookie pitchers – Early and Yankees starter Cam Schlittler – were dealing early on before the Yankees got to Early in the fourth and seized a 4-0 lead.

“We just didn’t play defense behind [Early],” Red Sox manager Alex Cora told ESPN’s Buster Olney after the fourth inning. “They didn’t hit the ball hard, and we just didn’t make outs.”