Dominic Thiem makes huge comeback, wins U.S. Open over Alexander Zverev2-0 set deficit comeback is first in American Grand Slam since 19499/14/2020, 1:08 AMSep 13 2020; Flushing Meadows, New York, USA; Dominic Thiem of Austria reacts after winning a point against Alexander Zverev of Germany (not pictured) in the men's singles final match on day fourteen of the 2020 U.S. Open tennis tournament at USTA Billie Jean King National Tennis Center. / © Danielle Parhizkaran-USA TODAY Sports