Daniil Medvedev is fast becoming the ultimate pantomime villain in world tennis.
The Russian became public enemy number one during last year's phenomenal run to the US Open final - the first grand slam decider of the 23-year-old's career.
Medvedev earned the ire of fans in New York with a series of angry outbursts, including a middle finger gesture to the crowd that saw him endlessly booed.
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In Sydney on Thursday night, the Russian sparked more controversy after a frustrated exchange with his opponent culminated in a "disgraceful" moment with the chair umpire.
After a verbal confrontation with Argentine Diego Schwartzman at the ATP Cup, which Medvedev said occurred when his opponent failed to acknowledge winning a point from a let cord, the Russian then took out his frustrations on official Mohamed Lahyani.
Or more specifically, the actual chair the umpire was perched upon.
The 23-year-old was infuriated by the umpire's handling of the situation, smashing the chair twice before he was ultimately handed a penalty.
Medvedev said he was initially frustrated when he was trying to find out whether he received a warning for the incident with Schwartzman, before Lahyani handed down a point penalty.
He was given a code violation for unsportsmanlike conduct but furious fans insisted the Russian's penalty should have been much harsher.
The Russian, who had won the first set, went on to lose the second before eventually prevailing 6-4 4-6 6-3.
Medvedev not fazed by potential punishment
"The second code violation for sure was deserved, so I don't argue," he said of striking the chair.
"In fact, why I got the second one was because I was arguing with the first one because I didn't hear it."
Medvedev said it was "not for him to decide" whether the highly unusual incident would be taken any further.
"Nothing happened to the chair, nothing happened to anybody, I didn't break my racquet," he said.
"I would say I got a code violation. I will get a fine. Usually when you get a code violation you get a fine for code violation. I don't think there is anything else to do."
After winning the first set Medvedev went on to lose the second following the incident but bounced back to claim the match, taking out the decider.
With Karen Khachanov winning his singles Russia claimed the tie and moved through to Saturday's semi-finals.