World No. 5 Tsitsipas has been fined $10,000 for unsportsmanlike conduct – the tournament’s highest single penalty to date.
After the match, he apologized for hitting a ball in the stands, which is considered a separate offense under Grand Slam rules.
Kyrgios, who won the match in four sets and meets USA’s Brandon Nakashima in the fourth round on Monday, was fined $4,000 for an audible profanity.
It means the Australian has been fined $14,000 so far in this tournament after being sanctioned for spitting at a spectator in his first-round match against Britain’s Paul Jubb, whom he said that he disrespected him.
After Saturday’s heated competition, Tsitsipas and Kyrgios continued to trade barbs off the pitch – the Greece fourth seed called his opponent “nasty” and a “bully”, while Kyrgios said Tsitsipas was “disliked” in the dressing room.
“I didn’t do anything disrespectful to Stefanos today,” he added. “I didn’t drill him with eggs. To come in here and say I bullied him, that’s just soft.”
Kyrgios has stirred controversy for his on-court behavior throughout his career, but he also played some of his best tennis matches at this year’s Wimbledon – notably when he swept past Filip Krajinovic by just an hour and 25 minutes in the second round.
The 27-year-old has reached the quarter-finals of a Grand Slam on two previous occasions – a record he could equal by beating Nakashima if the two meet on Center Court.