When the going gets tough, just quit.

That's the message tennis player Nick Kyrgios delivered through his actions at the Shanghai Masters on Thursday, when he pretty much completely stopped trying during a 6-3, 6-1 loss to Mischa Zverev.

Not only did Kyrgios embarrass himself by giving up, but he also got in a fight with a fan. After receiving understandable criticism from a man in the crowd, Kyrgios reportedly shouted back at him, "You want to come here and play? Sit down and shut up and watch."

The Australian was fined over $15,000 for his shenanigans: $10,000 for showing a "lack of best efforts," $5,000 for verbal abuse of a spectator and $1,500 for unsportsmanlike conduct.

After the match, Kyrgios was quick to make excuses for his behavior. In a post-match conference he claimed to be "physically and mentally tired" after "a lot of matches in a row."

"I wasn't so much frustrated," he said. "I just tapped out a little bit, I guess."

That's about as unsportsmanlike as it gets. We haven't seen that kind of implosion since ... well ... Nick Kyrgios.

That's right, back in the summer of 2015 Kyrgios lost a game on purpose at Wimbledon because he was mad at the umpire. It just shows how talented he must be to stay on the tour with exploits like this. If his mental game ever catches up to his physical tools, he might actually contend for some titles.

Well, at least he kept his socks and shoes on.