Tyler Herro Takes Ball to Groin From Ref in Hilarious Game Moment

Tyler Herro's nuts took a hit during Wednesday's game -- but it wasn't from an aggressive opponent ... it was courtesy of a referee!!

The low blow took place in the second quarter of the Miami Heat and Dallas Mavericks matchup at the American Airlines Center ... when Herro was about to shoot a technical free throw.

When the Heat guard stepped to the charity stripe, NBA official Jenna Reneau passed the ball ... but Herro wasn't paying attention and then BOOM -- direct hit on his manhood!

Reneau realized the damage that was done once she saw the NBA All-Star fold over in pain ... and walked over to make sure he was good.

It appeared Herro, 25, was okay after a few seconds ... and he was ultimately able to laugh it off once the hurt wore off.

The Heat? Not so much. They lost 108-118, even with Herro's 20 points. He did get some criticism for only scoring in the first half of the contest.