Paris - Norwegian Casper Ruud says that he is "done talking" about Nick Kyrgios' "behaviour" after the Australian said he was "boring" in a Twitter tirade.
The pair's first meeting at the Rome Masters earlier this year saw Kyrgios disqualified for throwing a chair onto the court in anger, with Ruud wildly celebrating his consequent win.
The world No 63 told the Tennisportalen website last week that Kyrgios was an "idiot" and was "totally crazy" in the match against him.
"Hey @CasperRuud98 next time you have something to say, I would appreciate you say it to my face, I'm sure you wouldn't run your mouth so much after that," Kyrgios hit back on Twitter.
"Until then I will continue to rather watch paint dry then watch you play tennis, boring af (as f**k).
"I also understand why you have to keep my name in your mouth, because people don't even realise that you play tennis."
But Ruud says he will not be criticising Kyrgios for his antics any longer.
"I'm done talking about whatever he does and I'm not going to be commenting anymore on him or his behaviour," he said after losing 6-4, 6-2 in the Paris Masters first round to Frenchman Adrian Mannarino on Monday in a match which finished at 11:45 p.m local time.
World No 30 Kyrgios was fined €20 000 following his Rome meltdown in just one of a string of controversies in his career.
The 24-year-old has since been fined $17 500 for unsportsmanlike conduct at Queen's in June, before having to pay an ATP Tour record $113 000 after an expletive-laden rant at umpire Fergus Murphy during the Cincinnati Masters in August.
Kyrgios also received a suspended 16-week ban.
The 20-year-old Ruud has qualified for next week's ATP NextGen Finals in Milan after a strong season which has seen him reach the French Open third round and break into the world's top 100.
"It was one of my biggest goals to be able to finish the season in Milan and we are there now," he said. "I'm looking forward to it a lot and it will be a great finish to the season."
Kyrgios, who has won two ATP titles this season, decided to skip the Paris Masters, where he has yet to make an appearance in his career.
But he has been named in Australia's team by Lleyton Hewitt after a 21-month absence for the inaugural Davis Cup finals in Madrid next month.