The 'Special Ks' pulled off a brilliant 7-6 (10-8) 6-3 victory over the Croatian duo, and Olympic gold medallists, in front of a boisterous crowd at Kia Arena on Friday.

Kyrgios and Kokkinakis were typically flamboyant and energetic, hyping up the crowd and celebrating with vigour and, according to Kyrgios, the fiery nature of the clash spilled over into the players' gym.

"Just letting you know after yesterday's chop fest in doubles my opponents coach and trainer proceeded to threaten to fight in the players gym," Kyrgios said on Twitter.

"Tennis is a soft soft sport @TKokkinakis all because I moved and hit them with a tennis ball."

Kokkinakis responded with laughing emojis as he backed up his doubles partner.

"That was crazy!! Mans thought it was @ufc," he said, quote-tweeting Kyrgios' original tweet.

Vision on Network Nine of the players' locker room after the alleged stoush showed an animated Kyrgios shaking his head and talking to his team.

Doubles world No.1 Pavic post-match suggested the boisterous crowd should "show some respect", echoing singles world No.2 Daniil Medvedev, who had expressed his frustration with noisy local fans after he beat Kyrgios on Thursday night.

"It's loud. They are pretty loud. Obviously they cheer for Aussies. It wouldn't hurt them to show some respect to all opponents, to other players," Pavic said.

"We saw yesterday also with Medvedev how it was.

"So, yeah, I mean, that's how they are here. We're used to that. But like I said, yeah, it wouldn't hurt them to show some respect."

Kyrgios and Kokkinakis are into the third round, leaving Pavic and Mektic to lick their wounds.

"It looks like just the guys played really well. They're a nasty team to beat here and that's it. We just fell short," Pavic said.

Wimbledon junior doubles champions in 2013, Kyrgios and Kokkinakis will next play either No.15 seeds Ariel Behar and Gonzalo Escobar or German duo Dominik Koepfer and Jan-Lennard Struff for a place in the quarter-finals.

Australian Associated Press