A Grand Slam champion has been called a “bad loser” after fans noticed a “pathetic” moment from his net exchange.

Three time Grand Slam champion Stan Wawrinka has drawn the ire of tennis fans across the globe after delivering some brutal words to an opponent.

Wawrinka was beaten by rising star Holger Rune in the opening round of the Paris Masters overnight 4-6, 7-5 7-6 and it was at the net when the Swiss star let rip.

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As the two men approached the net to shake hands following the back and forth tussle, Wawrinka leaned over and offered up some brutal advice for his younger opponent.

“My advice to you is that you stop acting like a baby on the court, OK?” Wawrinka was overhead saying by on-court microphones.

Wawrinka quickly walked away from his opponent, shaking the hand of the chair umpire before departing. Rune looked stunned by the words from the Grand Slam champ as he made his way off the court.

A clip of the frosty words of advice from Wawrinka quickly whipped around social media with fans slamming the 37-year-old.

“Now let’s pretend this was Djokovic who instead of acknowledging he lost a close match to the better player, called a teenager a crybaby for daring to beat him and not bow down to him. He would be absolutely hammered by the media and sanctimonious mob. Different rules for others,” one user wrote in response to the video.

Another wrote: “This was pathetic from Stan. Great match played by both and Stan couldn’t close it out. Unnecessary hostility at the handshake just feels like Stan being a bad loser. He should do better than this. Holger probably looked up to him as a kid as well.”

You can watch the frosty net moment in the video player above.

After the match, Rune’s mother and manager, Aneke, claimed Wawrinka had never said such things despite the microphone’s picking it up.

“It is hard to imagine that a sportsman like Stan would have said that,” Aneke told Danish outlet TV2.

“Then he would come across as an uncommonly bad loser. Holger has only mentioned that he wished him well with the results of the past weeks.”

Rune barely stepped a foot out of line as he claimed the three-set victory, but he has thrown himself into the centre of controversy in the past.

During the French Open the 19-year-old was locked in an intense battle with Norwegian star Casper Ruud with the two trading verbal barbs throughout the contest.

Rune accused Ruud of shouting in his face, an accusation Ruud immediately shut down as a “big lie”.

Ruud after the contest offered up some words of advice for the talented youngster.

“I don’t know Holger personally, but I have seen on TV that sometimes there can be a lot of drama,” Ruud said.

“He’s young and new, so that’s excusable, but when you’re on a big stage, it might be time to grow up a bit.”

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