MONTREAL -- French Open champion Stan Wawrinka urged tennis authorities on Thursday to take action against Nick Kyrgios for an "unacceptable" comment during a match at the Rogers Cup.
Wawrinka wrote on his Twitter account that the Australian's words were "not only unacceptable but also beyond belief."
What was said I wouldn't say to my worst enemy. To stop so low is not only unacceptable but also beyond belief.
— Stanislas Wawrinka (@stanwawrinka) August 13, 2015
There is no need for this kind of behaviour on or off the court and I hope the governing body of this sport does not stand...
— Stanislas Wawrinka (@stanwawrinka) August 13, 2015
... for this and stands up for the integrity of this sport that we have worked so hard to build.
— Stanislas Wawrinka (@stanwawrinka) August 13, 2015
A courtside microphone picked up the 20-year-old Kyrgios saying that Australian player Thanasi Kokkinakis had slept with a player who is reportedly Wawrinka's girlfriend.
"There is no need for this kind of behaviour on or off the court and I hope the governing body of this sport does not stand for this," the 30-year-old Wawrinka wrote on Twitter.
Wawrinka, ranked fifth in the world, announced in April that he had separated from his wife, with whom he has a daughter.
Wawrinka has since been linked with 19-year-old Donna Vekic of Croatia, who is ranked 127th.
Vekic played mixed doubles with Kokkinakis, also 19 and ranked No. 76, at the 2014 Australian Open as a wild-card entry.
Kyrgios beat Wawrinka on Wednesday when the Swiss retired with a lower-back injury while trailing 4-0 in the third set.
In a post-match interview on court, Kyrgios said Wawrinka had provoked him.
"He was getting a bit lippy at me so, I don't know, it's just in-the-moment sort of stuff," Kyrgios said. "I don't really know, I just said it."
