Altmaier Upsets Tsitsipas, Sparks Post-US Open Confrontation

At the 2025 US Open, Daniel Altmaier upset Stefanos Tsitsipas in a tense five-set match, marking Altmaier's first top-50 Grand Slam win and his progress to the round of 32 at a major outside the French Open. The match became controversial due to Altmaier's use of an underarm serve, a legal but seldom-used tactic that angered Tsitsipas, who confronted Altmaier at the net after the match. Tsitsipas' frustration reflected a difficult season marked by early exits in major tournaments and coaching violations, including a warning issued to his coaching team during this match for giving instructions. Altmaier downplayed the post-match confrontation, attributing Tsitsipas' comments to the heat of the moment and emphasizing his focus on personal performance and belief. The incident highlighted ongoing tensions in professional tennis about sportsmanship and strategic play, with Altmaier preparing to face Alex De Minaur in the next round. Tsitsipas' season continues to be challenging, as he has yet to advance past the second round in recent majors.