Daniil Medvedev caused mayhem at the 2025 US Open after taking issue with the chair umpire's ruling during his first-round clash. The Russian's actions caused a significant delay during a crucial moment of the match.After his disappointing campaigns at Wimbledon and the French Open, Medvedev appeared set for another first-round exit at a Major this season as Bonzi served for the match in the third set. But that's when Medvedev had his heated outburst, which led to a turn in the tide.Benjamin Bonzi missed his first serve on match point at 5-4 in the third set. Right at that moment, chair umpire Greg Allensworth chastised a cameraman for attempting to leave the court. He then awarded Bonzi another first serve due to the interruption.Daniil Medvedev did not take kindly to the chair umpire's ruling, and he urged the New York crowd to join him in protesting against the call. The Russian went up to Allensworth and furiously confronted him, even alleging that the umpire simply wanted the match to end so he could return home."Are you a man? Are you a man? why are you shaking? What’s wrong huh? He wants to go home guys. He doesn't like to be here. He gets paid by the match not by the hour," Daniil Medvedev said.Medvedev also repeatedly shouted, "What did Reilly Opelka say!", referring to an incident at the 2025 Dallas Open when the American called Greg Allensworth the "worst" umpire on tour. Opelka had called for Allensworth to be "penalized" after the umpire's handling of his encounter with a heckler.After Daniil Medvedev incited the US Open crowd, they refused to allow Benjamin Bonzi to serve for the match as they continued to shout for over five minutes. The Russian, meanwhile, sarcastically blew kisses towards Greg Allensworth and showed his appreciation to the spectators by forming a heart with his hands.When play finally resumed, Medvedev managed to fend off the match point, before going on to break Bonzi's serve. The 29-year-old then won the third-set tiebreak and clinched the fourth set 6-0 to force a decider. Despite Medvedev's hard-fought comeback attempt, Bonzi ultimately claimed a 6-3, 7-5, 6-7(5), 0-6, 6-4 victory to advance to the second round of the US Open.