Stefanos Tsitsipas confronts Daniel Altmaier about underhand serve in tense US Open moment.#tennis #usopen #stefanostsitsipas #danielaltmaier #tennismatch Subscribe and don't miss out on all the key news, highlights, and interviews about the Yankees, Mets, Giants, Jets, Knicks, Nets, Rangers, Devils, Islanders and what's buzzing in the sports world too! Catch the latest news here: https://nypost.com/sports/Follow The New York Post Sports on: Twitter - https://twitter.com/nypostsports Facebook - https://www.facebook.com/nypostsports/
