Photos: Celebrity sightings at the US Open 2021 Actors Brad Pitt and Bradley Cooper watch the Men's Singles final match between Daniil Medvedev of Russia and Novak Djokovic of Serbia on Day Fourteen of the 2021 US Open at the USTA Billie Jean King National Tennis Center on September 12, 2021, in the Flushing neighborhood of the Queens borough of New York City. (Sarah Stier/Getty Images)