REUTERS: Nick Kyrgios said he would not listen to criticism from Rafa Nadal, who accused the Australian of lacking respect "for the public, the opponent and toward himself" following their match at the Acapulco International on Wednesday.
Kyrgios overcame a bout of nausea to beat Nadal in a three-hour, three-set thriller, during which the Australian used a mix of typically audacious drop shots and brute power to win 3-6 7-6(2) 7-6(6).
The quick-playing Kyrgios tried an underarm serve late on in the encounter in an effort to catch Nadal off guard, after the 17-times grand slam champion had moved far behind the baseline to receive.
The Australian also screamed at the packed crowd to "shut up" at one stage, using an expletive that earned him a warning from the chair umpire. Nadal had also expressed annoyance with the spectators' noise.
Kyrgios improved his career record against Nadal to 3-3 but his antics on court during the second round match seemingly annoyed the world number two.
"He's a player who has enormous talent, could be winning grand slams or fighting for the top positions of the ranking, but there is a reason why he is where he is," Nadal said.
"He lacks respect for the public, the opponent and toward himself," added Nadal, who said he did not think Kyrgios was a "bad guy".
World number 72 Kyrgios, however, shrugged off the criticism.
"He doesn't know the journey I've been through. He doesn't know anything about me so I'm not going to listen at all," the Australian told a news conference.
"I'm not going to comment on his game. I've got my game, he's got his own game."
Kyrgios, who takes very little time between points on serve, defended his quick play.
"He's very slow in-between points," he said of Nadal.
"The rule in the book says you have to play at the speed of the server."
Kyrgios will play Switzerland's Stan Wawrinka in the quarter-finals.
(Reporting by Andrew Both in Cary, North Carolina; Editing by Toby Davis)