Nick Kyrgios has responded after Nicolas Mahut declared he “let himself go”.

The former doubles No. 1 slammed Kyrgios for his latest rant about Jannik Sinner and claimed the Australian wouldn’t win if he faced Sinner on the court.

But the 29-year-old has now hit back, suggesting that Mahut’s mentality helped Roger Federer and the rest of the Big Three become the greatest.

“If I played him in the Australian Open, I’d get every person in the crowd to get on him. I would turn into an absolute riot. All respect would go out the window and I would just do anything to win,” the 2022 Wimbledon finalist said.

Mahut took issue with Kyrgios’ comments, telling Eurosport: “Sinner has never disrespected anyone and he is the No. 1 in the world. There is no need to let yourself go like this.”

The Frenchman also thought Sinner would get a routine victory over Kyrgios if they did meet Down Under, given that the Australian is about to return from a two-year injury layoff.

Former world No. 13 Kyrgios has fired back at Mahut, arguing that he had no belief. “I have people like Mahut telling me to be realistic,” he told Telecom Asia.

“He was an amazing doubles player, a Grand Slam champion, no doubt, but he didn’t have the singles career I’ve had. That’s probably why he has his opinion.

“But on the singles court, he never had the belief I have, so that opinion means nothing to me. I’ve achieved way more things playing singles than Mahut could have in his entire career.”

Kyrgios, who has beaten each member of the Big Three, also claimed that players who thought the same had never been able to outdo Federer, Rafael Nadal or Novak Djokovic.

He added: “That belief is what separates players. Federer, Nadal, Djokovic – they were the greatest because people were defeated before they even stepped on the court with them. I don’t want to be that player. I’ll always back my ability and my belief.”

Kyrgios recently competed in the World Tennis League exhibition in Abu Dhabi to prepare for his comeback. He lost his only singles set to Andrey Rublev 6-4.

The 29-year-old will be back on the official ATP Tour at the end of the month after entering the Brisbane International. He will then head to Melbourne for the Australian Open.

Kyrgios has played just one match in the last two years after battling knee and wrist injuries. The Australian is now unranked but has a protected ranking of No. 21, allowing him to enter top tournaments.