Third-ranked Stefanos Tsitsipas has been reduced to a US Open punchline for extended disruptive toilet breaks during matches, with victims Alexander Zverev and Andy Murray ripping him on Tuesday.

German fourth seed Zverev, who accused Tsitsipas of getting improper coaching during his toilet break in a match at Cincinnati, went out of his way to hurl a zinger at the Greek star after a first-round triumph.