Italian Open: Nick Kyrgios serves underarm during win over Daniil Medvedev

Nick Kyrgios

Nick Kyrgios

Kyrgios went on to take the first set 6-3. "It was a high percentage play", Kyrgios told Tennis Channel.

"I was trying to throw him off his game because I knew he loves rhythm". I thought the crowd was a lot of fun.

Nick Kyrgios began his Rome Masters with an underarm serve. Against Medvedev he showed no concern at all, using the tactic on the opening point of the match - and winning the point in the process.

He did so against Rafael Nadal in at the Mexican Open in February where the Spaniard criticised Kyrgios saying he "lacks of respect to the public, his rival and himself".

Kyrgios' performance against Medvedev had it all, including one point where the ball sat up for Medvedev to drill a victor, and Kyrgios turned around on the clay and bent over to show his backside to the Russian.

Medvedev received on-court treatment for a lower back injury before the second set and later smashed a racquet on the ground in frustration.

"Busted out the underarm serve on the first point because he was way back and I had an easy forehand".

But Kyrgios quickly gained the ascendancy in the decider, breaking the Russian in his first service game.

Kyrgios, who ended the match with four aces, plays Norway's Casper Ruud next.

"Because he does not want to show that, for him it's hard to play with that opponent".

A possible round of 16 clash looms against seventh seed Juan Martin del Potro.

World No.5 Alexander Zverev continued his poor recent form as he crashed out after a 7-5 7-5 defeat by home favourite Matteo Berrettini.