Japanese tennis star Yoshihito Nishioka “lost his mind” in fiery scenes during the Cincinnati Open on Thursday.

Going up against the fifth seed Hubert Hurkacz, Nishioka was in control of the contest before it all fell apart.

After dropping the first set, Hurkacz fought back to win the second set tiebreak before flexing his muscles in the deciding set.

As the Polish star began to run away with the match, Nishioka imploded and started smashing balls into the crowd as one commentator proclaimed he had “lost his mind”.

After Hurkacz secured a break to go up 3-1, Nishioka launched a ball high into the stands before asking a nearby ballgirl for another that he sent into orbit.

“(Hurkacz) is going to start 15-0 up as well. He’s snapped,” commentator Barry Cowan said.

A split second later chair umpire Aurelie Tourte handed down the punishment to the Japanese star.

“Code violation, unsportsmanlike conduct. Point penalty, Mr Nishioka,” Tourte said.

Frustration once again got the better of Nishioka moments later as he sent a third ball into the stands.

The explosive outburst, immediately after the unsportsmanlike conduct saw the world No. 52 slapped with a game penalty.

“Code violation, ball abuse. Game penalty, Nishioka,” Tourte announced.

One commentator couldn’t believe what they’d just seen unfold in front of their eyes.

“What is he doing? He’s completely lost his mind. Self-destruction if you like. I mean, he knows the rules, he knows exactly what’s going to happen,” he said.

As Nishioka lost his mind, Hurkacz kept his cool as he went on to win the contest 3-6, 7-6, 6-1 and set up a contest against Italian Flavio Cobolli, who advanced when compatriot Luca Darderi retired trailing 7-6, 3-1 with an apparent illness.

The Japanese star apologized following the match as he looks ahead to the final grand slam on the calendar, the US Open.

“I had a lot of support here and in the U.S. as well, and in my home country,” Nishioka said. “I had a good result here, beating (Miomir) Kecmanovic, who is a great player. I had good play against Hubi in our first meeting, but in the third set, I tanked a little bit.

“I’m very sorry to my fans: I showed my best tennis until the second set when I couldn’t. Hopefully, there’ll be some luck for me at the US Open. I think my feel in tennis is better and better each day. I have to take care of my body a little bit and get ready for the US Open. I think I can play good tennis there.”