Daniil Medvedev has suffered a complete meltdown in an extraordinary Australian Open semi-final win over Stefanos Tsitsipas on Friday night.
Medvedev will meet Rafael Nadal in the men's final on Sunday night after the Russian star put on a pyrotechnic display on his way to what was a heated victory.
Nadal earlier triumphed 6-2 6-3 3-6 6-3 against Matteo Berrettini in a gripping four set battle.
Nobody could have predicted what came afterwards when Medvedev stepped onto the court.
His 7-6 4-6 6-4 6-1 victory has been overshadowed by a moment where he lost the plot in an angry verbal attack on the chair umpire.
Medvedev launched into an angry tirade at the chair umpire after he lost his serve late in the second set.
After first complaining about fans yelling out during his serve, Medvedev turned his fury towards the umpire when he continued to complain about Tsitsipas appearing to be gaining an advantage from coaching advice coming from his father in his players box.
Medvedev screamed at the chair umpire to "look at me" at one point and repeatedly asked the umpire if he was "stupid".
Tsitsipas fired a parting shot at Medvedev in his post match press conference, attacking the 25-year-old's brash reputation.
"It's funny. I don't pay attention to the stuff," he said of Medvedev's blow up.
"I know players like to do this stuff to throw you off mentally. It could be maybe a tactic. It's all right. He's not the most mature person anyways."
Despite the extraordinary blow up, Medvedev was not given a code violation for attacking the official.
"Are you mad? Are you mad? His father can coach every point," he said in a tirade caught on TV cameras.
"Are you stupid? His father can talk every point? His father can talk every point? Answer my question. Will you answer my question. Will you answer my question? Can you answer my question? Can you answer my question, please? Can his father talk every point?"
He went on to say to the umpire: "Oh my god. Oh my god, you are so bad, man. How can you be so bad in semi-final your answer? Look at me. I'm talking to you!".
Medvedev then attacked the umpire again when Tsitsipas wrapped up the second set in the following service game.
He went at the umpire furiously before storming off the court at the end of the set, calling the official a "small cat".
He continued to demand the umpire give Tsitsipas a code violation.
"You understand Greek? You understand Greek? Next time it should be a code violation," he said.
"If you don't, you are, how can I call it, a small cat. Repeat the answer to my question. Will you answer my question?"
Tsitsipas has received several warnings this tournament for receiving coaching advice in the middle of his matches.
Tsitsipas was eventually given a code violation warning for coaching early and grinned after learning officials had conducted an operation to catch his father in the act.
The world No. 4 was not grinning in the moments soon after and he went on to lose all five service games that followed the code violation warning.
Tennis commentators from around the world were impressed and highly amused at the sly craft from tournament officials.
Tournament referee Wayne McKewen and veteran umpire Eva Asderaki-Moore secretly positioned themselves in the mouth of the players' tunnel directly under Tsitsipas' players box.
Asderaki-Moore, who speaks Greek, only needed to hide for a few minutes before she signalled to the chair umpire that she had heard someone inside Tsitsipas' box giving coaching advice.
Tennis great Jim Courier described the situation as a successful "sting operation" to catch Tsitsipas out. The 23-year-old is a serial offender when it comes to receiving on-court coaching and has developed a reputation for shamelessly ignoring the rules.
The match finished with the two combatants sharing an icy handshake at the net before the Melbourne crowd booed Medvedev as he stopped onto the middle of the court.
The No. 2 seed was booed again as he walked out to conduct his on-court interview with Jim Courier.
He was then booed for a third time when he said he would be having dinner on Saturday night and might not watch Ash Barty playing in the women's singles final.
Courier said he asked Medvedev about his plans in an attempt to help the Russian endear himself with the hostile crowd, but his answer didn't help.