HOUSTON — The man who caused Astros reliever Ken Giles to punch himself in the face didn’t see the act, but some of his teammates had a look at it live and on video.

“I didn’t see it,’’ Gary Sanchez of Giles assaulting himself after giving up a three-run homer to the catcher in the top of the ninth Tuesday night that fractured a scoreless game and led the Yankees to a sensational 4-0 victory at Minute Maid Park. “I was running the bases and then in the dugout.’’

With first base open, Giles wasn’t instructed to intentionally walk Sanchez and got burned when he hit the first pitch 423 feet over the center-field fence.

“I didn’t see it, I heard about it,’’ manager Aaron Boone said of Giles punishing his mug for a slider that begged to be punished.