Controversial Australian tennis player Nick Kyrgios has unleashed a tirade on his sport, calling it "biased" and "ruined" on Wednesday during his fourth round win at the Miami Masters.

The 20-year-old from Canberra defeated 51st-ranked Russian Andrey Kuznetsov 7-6 (7-3), 6-3 to become the first Australian in the Miami quarter-finals since Lleyton Hewitt's 2002 semi-final run.

But a dispute flared in the first set after chair umpire Cedric Mourier called a code violation against Kyrgios for swatting a ball tossed his way by a ballperson into the stands.

On the next changeover, Kyrgios told the umpire his action was not intentional and said a star player such as 14-time major champion Rafael Nadal would not have been called out for the same action.

"Anyone else, like Rafa did that, you would keep it cool," Kyrgios told the umpire.

"This game is biased as anything. You all know it as well. It's biased as shit, this game. What else has it got to hide? It's ruined. Absolutely ruined."

Responding to questions after the match, Kyrgios said only that he stood by the comments.

Kyrgios, the youngest player ranked in the ATP top 30 at 26th, will face Canadian 12th seed Milos Raonic on Friday (AEDT) for a semi-final berth.

Off to a career-best 13-3 start that includes his first ATP title last month at Marseille, Kyrgios has a long track record of making off-colour remarks, including his foul-mouthed sledging of Swiss star Stan Wawrinka at the Montreal Masters last August, that earned him a suspended 28-day ban and a $US25,000 ($32,800) fine.

Earlier this month he fumed at an umpire at the Indian Wells tournament after being docked a point for swearing.

AFP/ABC