Fabian Marozsan defeated Joao Fonseca 6–3, 7–6 in the first round of the ATP Rome Masters on clay on 8 May 2025, producing an upset victory against the pre-match favourite. Fonseca entered as the stronger betting preference at 1.41 odds to Marozsan's 3.13, but the Hungarian player executed a composed performance to claim the match in straight sets. The second set went to a tiebreak, where Marozsan secured the decisive points to advance. The result demonstrates Marozsan's ability to compete against seeded opposition on the clay courts of Rome, a surface where consistency and tactical awareness often prove decisive in early-round encounters.