Fortunately, the kid appeared to be OK after Kyrgios apologized with a gift racket.

The wild play all went down Monday during Kyrgios' doubles event with partner Thanasi Kokkinakis ... when Kyrgios got pissed over a missed serve.

You can see in footage from the Open, Kyrgios rifled a ball into the ground, and it ended up ricocheting straight into the stands and right into a kid's stomach.

The boy was so visibly hurt and upset ... Kyrgios himself was shaken up on the court.

Nick, though, collected himself and immediately grabbed one of his spare rackets to make up for the major blunder. And, it seemed the child was going to be just fine after the present.

"I saw it heading towards the kid and I thought, "Oh, no, I am getting defaulted," Kyrgios said of the scene to Channel Nine after the match. "I was glad he was OK and I gave him the racket."

This isn't the first time Kyrgios has made headlines at this month's tourney -- just last week, the 26-year-old took a swig of a fan's beer after defeating his opponent.

The fans in attendance loved it ... but the gesture didn't come without controversy, as some wondered if event organizers would come down hard on the Aussie ... given the COVID drama that went down with Novak Djokovic in the buildup to the tourney.

But, Nick has yet to face any discipline for the not-so-safe action.