Altmaier tops Tsitsipas in five-set US Open to reach third round

Daniel Altmaier upset Stefanos Tsitsipas in a five set marathon at the U.S. Open on Thursday, rallying to a 7-6(5), 1-6, 4-6, 6-3, 7-5 victory at the USTA Billie Jean King National Tennis Center in New York and advancing to the third round. The match lasted four hours and 26 minutes and ended with a heated exchange at the net after Tsitsipas confronted Altmaier over the German's use of an underarm serve.

Momentum swung repeatedly through the contest. Tsitsipas, who opened strongly, collected 17 aces and 72 winners, according to match statistics, and held a match point on Altmaier's serve in the 10th game of the fifth set. Altmaier saved that match point and broke in the following game to seal the win. The German used underarm serves multiple times during a fourth set comeback, a tactic that is legal but uncommon and that drew visible displeasure from Tsitsipas.

As the players met at the net, Tsitsipas was heard telling Altmaier, "Next time don't wonder why I hit you, OK?" He later reiterated, "No, I'm just saying, if you serve underarm," referencing a forehand earlier in the match that struck Altmaier's body; Tsitsipas had apologised at the time. Altmaier walked away without...