Nick Kyrgios has savaged Casper Ruud on social media, calling the Norwegian youngster "boring af" and urging him not to "run your mouth."
Kyrgios' clapback comes days after Ruud was quoted as calling the Australian "an idioton the court."
Their beef goes back to a contentious meeting at the Rome Masters in May, when the Australian was defaulted during their second round match.
Kyrgios had smashed a racquet, kicked a drink bottle and thrown a chair by the time he stalked off court and was later fined.
MORE: Casper Ruud hits out at Nick Kyrgios
At the time, Ruud said Kyrgios should have copped a suspension, with Kyrgios posting a tweet he later deleted, calling the 20-year-old boring.
Fast forward five months, and Ruud was told tennis writer Alex Theodoridis of Tennisportalen that Kyrgios "acted like an idiot on court."
The comments didn't go down well with the world number 30.
Taking to Twitter to hit back, Kyrgios didn't pull and punches.
"Hey @CasperRuud98 next time you have something to say, I would appreciate you say it to my face," he wrote.
"I'm sure you wouldn't run your mouth so much after that.
"Until then I will continue to rather watch paint dry (than) watch you play tennis, boring af."
In a second tweet, Kyrgios went even further, ending with the ultimate insult by calling Ruud "champ."
"But again, I also understand why you have to keep my name in your mouth, because people don't even realise that you play tennis.
"Goodluck in Milan champ x."
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. Until then I will continue to rather watch paint dry then watch you play tennis, boring af.
— Nicholas Kyrgios (@NickKyrgios) October 24, 2019
But again, I also understand why you have to keep my name in your mouth, because people dont even realise that you play tennis 😂 goodluck in Milan champ x
— Nicholas Kyrgios (@NickKyrgios) October 24, 2019
