Scary scene during the Yankees vs. Orioles game Wednesday night ... a cameraman was drilled in the forehead by an errant throw -- and the baseball did so much damage, the guy had to spend the evening in the hospital.

It happened during the fifth inning ... when Orioles shortstop Gunnar Henderson hurried a throw to first base in an attempt to get Anthony Volpe out.

The toss, though, sailed high on the Baltimore rookie ... and it ended up going into a dugout where YES Network cameraman Pete Stendel had been filming.

Video from the game's broadcast shows the baseball caught Stendel flush ... and he immediately crumpled to the ground in pain. Trainers rushed over to help him -- before they strapped him to a backboard and took him away from the field.

Stendel was able to give the crowd a wave while he was being transferred out of the stadium ... and, fortunately, YES Network officials said later in the evening he was conscious while he undergoing further examination at a local medical facility.

Yankees manager Aaron Boone, meanwhile, said after the game the whole thing was horrifying.

"Definitely praying for him," Boone said following NY's 6-3 loss. "It was good to see him, obviously, coherent and obviously raising his hand going off."

Get well soon, Pete.