21-year-old Australian tennis player Nick Kyrgios got into an argument with a fan and blatantly tanked a match

Koji Sasahara/AP

Less than a week after winning the biggest event of his young career at the Japan Open, 21-year-old Australian tennis player Nick Kyrgios reverted to his maddeningly immature ways on Tuesday at the Shanghai Masters, not even pretending to try in a 48-minute loss to a qualifier. 

In the first set against the German Mischa Zverev, Kyrgios quickly found himself down a break, 3-1. From there, he started dinking his serve over the net, making no effort on returns, and at one point was reportedly scolded by the chair umpire, who told him, "Nick, you can't play like that. It's just not professional. This is a professional tournament." 

Later, during a changeover, Kyrgios pleaded with the umpire: "Can you call time so I can finish this match and go home?"

Toward the end of the match, an angered fan yelled at him to "respect the game" and "respect the people", Kyrgios stopped the match to engage with him. 

"You wanna come here and play? Sit down and shut up and watch," he said, according to the Daily Mail.

Here are some of the highlights: 

After the match, Kyrgios told the media that he was tired from his busy schedule. When a reporter followed up and asked about his lack of effort, Kyrgios hit back.

From the Daily Mail:

"I don't owe them anything. It's my choice. If you don't like it, I didn't ask you to come watch. Just leave. 

"If you're so good at giving advice and so good at tennis, why aren't you as good as me? Why aren't you on the tour?"

"You want to buy a ticket? Come watch me. You know I'm unpredictable. It's your choice. I don't owe you anything. Doesn't affect how I sleep at night.'"

Eventually, Kyrgios took to Twitter to apologize for his behavior: 

The contrast between Kyrgios' impressive tournament win at the Japan Open and his inexcusable performance in Shanghai is what makes him so maddening.

The talent is there - unquestionably. En route to the title in Japan, Kyrgios knocked off 2014 US Open winner and world no. 11 Marin Cilic in the semifinal, and followed that up with an three-set victory over world no. 12 David Goffin. 

And yet Kyrigos also regularly talks openly about how he doesn't enjoy playing tennis, and how he wishes he were an NBA player instead. At Wimbledon in 2015, he showed his talent by reaching the fourth round, but then stopped trying against Richard Gasquet because he was mad at the chair umpire.

Kyrigos is currently ranked 14th in the world. Right now, it seems equally likely that he'll break through and win a Grand Slam within the next year, or just quit tennis altogether.