Nick Kyrgios claimed he was threatened in the players' gym at Melbourne Park after he and Thanasi Kokkinakis upset top-seeded Croatian pair Nikola Mektic and Mate Pavic in an Australian Open second-round doubles match in front of a raucous home crowd on Friday.
The Australians won the match 7-6 (8), 6-3 and the teams shook hands at the net.
The trouble started, according to Kyrgios, when a member of the support team approached him after the match.
"Just letting you know after yesterday's chop fest in doubles my opponent's coach and trainer proceeded to threaten to fight in the players gym ... tennis is a soft soft sport ... all because I moved and hit them with a tennis ball," Kyrgios wrote Saturday on Twitter.
Kokkinakis, describing it in a social media post, said, "That was crazy!!" and joked about it being like UFC.