One minute, Brandon Prust was finishing a check on Pittsburgh’s Tyler Kennedy. The next, he was staring up at the ceiling of the Garden after being caught flush on the chin by a left hook from the Penguins’ Jordan Staal.

“Yeah, it was kind of surprising,” Prust said after the Rangers’ 4-3 shootout loss to the Penguins. “It happened kind of quick. He just kind of caught me on my sweet spot, and dropped me for a second.”

The play came at the 15:27 mark of the second period, shortly after Chris Kunitz had scored Pittsburgh’s third straight goal to give the Penguins a 3-2 lead. A scrum had developed in front of the teams’ benches, and Prust came in and checked Kennedy.

Staal then came over to defend his teammate, checking Prust before unloading the left hand that sent Prust crashing to the ice — and sent Staal to the locker room with a five-minute maximum penalty and an ejection.

The Rangers eventually scored the game-tying goal during the ensuing power play, when Ryan Callahan deflected Michael Del Zotto’s shot from the point past Penguins goalie Marc-Andre Fleury with 12.5 seconds remaining in the second period.

“I don’t know him,” Rangers coach John Tortorella said. “I respect the Staal family a obviously we have one, and I’ve watched them all play.

“I think you could tell, when it happened, at least when I watched it, that I think he knew that he made a mistake there.”

Penguins coach Dan Bylsma wasn’t convinced the officals made the correct decision in ejecting his center.

“I wasn’t particularly fond of the call,” he said. “It certainly was a scrum, and both guys were taking their shots . . . I’m not sure the penalty was warranted.”

“Certainly [the league is] going to, and already have, looked at the situation and will make a judgment on that, but that’s not our call.”

Rangers defenseman Marc Staal said he’d never seen his brother get ejected from a game before, but said he didn’t seen the play.

“No, I was looking at the boards,” he said. “I turned around, and there was a scrum.”

It was an eventful game for Prust, who also scored the opening goal 3:52 into the first period, and also fought Penguins defenseman Deryk Engelland early in the second period.

Prust, who said he was checked out after the game by the team’s doctors and was fine, didn’t play for the rest of the second period, though both he and Tortorella said he could have returned.

He eventually returned in the third period, logging seven shifts and 5:40 of ice time, and said he had no hard feelings about the play.

“Stuff happens out on the ice,” he said. “I was kind of happy he did it . . . we got a five-minute power play out of it, so thank you.”