Tennis' Mike Bryan Pretended To Shoot Official With Racket, Fined $10k

U.S. doubles tennis star Mike Bryan pretended to load his racket like a gun and shoot a line judge over an incorrect call ... and the guy was fined $10,000 for the gesture.

It all went down Sunday at the U.S. Open ... when Bryan challenged an "in" call during his doubles match against Federico Delbonis and Roberto Carballés Baena.

Turns out, Bryan was right to protest -- the replay showed the ball was out -- and as part of his celebration for the successful challenge, he pointed his racket at a line judge and pretended to shoot.

Bryan was immediately hit with a code violation for unsportsmanlike conduct ... with chair umpire Mariana Alves telling him, "I don't think that was appropriate."

The U.S. Open later fined 41-year-old Bryan $10k ... with U.S. Tennis Association spokesman, Brendan McIntyre, telling the New York Times, "We thought it warranted that amount."

When contacted about the gesture and the fine by the NY Times ... Bryan released a statement apologizing for the act.

"We won the point and the gesture was meant to be playful. But, given the recent news and political climate I understand how my gesture could be viewed as insensitive."

Bryan added, "I promise that I will never do anything like this again."