Daniil Medvedev raged at the chair umpire during his Australian Open semifinal with Stefanos Tsitsipas
Daniil Medvedev went on the rampage at the Australian Open as the Russian second seed unleashed a verbal volley at the chair umpire over claims that Greek rival Stefanos Tsitsipas was breaking the rules by receiving mid-match coaching.
After taking the first set of their semifinal in Melbourne, Medvedev was on course to drop the second after being broken twice by Tsitsipas - a rival with whom he has a tense history after previous on-court clashes.
That track record of animosity took a new turn on Friday at Rod Laver Arena as Medvedev exploded at match umpire Jaume Campistol, claiming that Tsitsipas was receiving coaching from his father in the stands - which is against the rules.
"His father can talk every point. Are you stupid?" Medvedev screamed.
"His father can talk every point. Answer my question. Can his father talk every point?
"Oh my God, how can you be so bad in the semifinal of a Grand Slam?" Medvedev raged.
"Look at me! I'm talking to you!"
"What do you want?" Campistol replied.
"To give him coaching [violation] because his father is talking every point," Medvedev yelled.
Fourth seed Tsitsipas served out the set to level things up at 1-1 amid the explosive scenes, but the Greek did receive a time warning for his slow play.
Medvedev stormed off between sets for a change of clothing, appearing to call the umpire "a small cat" along the way as the Russian aims to reach a second successive final in Melbourne.
The 25-year-old Medvedev is the reigning US Open champion and could become the first man to follow up a maiden Grand Slam title with victory on his next appearance at a Major.
Earlier on Friday, Rafael Nadal booked his spot in Sunday's Australian Open final with victory over Matteo Berrettini, as the Spaniard eyes what could be a record 21st Grand Slam title.