Rafael Nadal's Return Shot Nails Ball Girl in Face, Star Apologizes With Kiss

Scary moment for tennis superstar Rafael Nadal at the Australian Open ... he hit a return shot right off a ball girl's face ... but he made up for it by kissing her owie!!

Rafa was in the middle of his 2nd round match with Federico Delbonis on Thursday, when he ripped a vicious return shot that ended up missing his target and going wide.

The shot hit the ball girl that was standing near the umpire's chair ... and Nadal rushed over to make sure she was okay.

After exchanging a few words, Nadal gave her an apology kiss on the cheek before returning to the match.

Nadal went on to win and move on to the 3rd round ... but admitted he was shook by the incident.

"For her, it was probably not a good moment,” Nadal said after the win ... "She is a super-brave girl."

Nadal added, "It was one of my most scary moments that I had on the tennis court, as the ball went straight onto her head."

The brave ball girl didn't leave empty-handed ... 'cause Nadal gave her his headband after the win!!