Serena Williams of the United States reacts after losing the first set against Bianca Andreescu of Canada in the women's singles final on day thirteen of the 2019 US Open tennis tournament at USTA Billie Jean King National Tennis Center. Mandatory Credit: Danielle Parhizkaran-USA TODAY Sports

Serena Williams of the United States reacts after losing to Bianca Andreescu of Canada in the women's singles final on day thirteen of the 2019 US Open tennis tournament at USTA Billie Jean King National Tennis Center. Mandatory Credit: Danielle Parhizkaran-USA TODAY Sports

Bianca Andreescu of Canada celebrates match point against Serena Williams of the United States in the women's singles final on day thirteen of the 2019 US Open tennis tournament at USTA Billie Jean King National Tennis Center. Mandatory Credit: Danielle Parhizkaran-USA TODAY Sports TPX IMAGES OF THE DAY

Bianca Andreescu of Canada with the US Open championship trophy after beating Serena Williams of the USA in the women’s singles final on day thirteen of the 2019 U.S. Open tennis tournament at USTA Billie Jean King National Tennis Center. Mandatory Credit: Robert Deutsch-USA TODAY Sports

Meghan, Dutchess of Sussex, sits in the player?s box of Serena Williams of the United States (not pictured) prior to her match against Bianca Andreescu of Canada (not pictured) in the women?s final on day thirteen of the 2019 US Open tennis tournament at USTA Billie Jean King National Tennis Center. Mandatory Credit: Geoff Burke-USA TODAY Sports

Bianca Andreescu of Canada celebrates match point against Serena Williams of the United States in the women's singles final on day thirteen of the 2019 US Open tennis tournament at USTA Billie Jean King National Tennis Center. Mandatory Credit: Robert Deutsch-USA TODAY Sports

Bianca Andreescu of Canada hits to Serena Williams of the USA in the women’s final match on day thirteen of the 2019 U.S. Open tennis tournament at USTA Billie Jean King National Tennis Center. Mandatory Credit: Robert Deutsch-USA TODAY Sports

Serena Williams of the United States hits a forehand against Bianca Andreescu of Canada (not pictured) in the women?s final on day thirteen of the 2019 US Open tennis tournament at USTA Billie Jean King National Tennis Center. Mandatory Credit: Geoff Burke-USA TODAY Sports

Bianca Andreescu of Canada (left) greets Serena Williams of the USA after the women’s singles final on day thirteen of the 2019 U.S. Open tennis tournament at USTA Billie Jean King National Tennis Center. Mandatory Credit: Robert Deutsch-USA TODAY Sports

Bianca Andreescu of Canada hits to Serena Williams of the USA in the women’s final match on day thirteen of the 2019 U.S. Open tennis tournament at USTA Billie Jean King National Tennis Center. Mandatory Credit: Robert Deutsch-USA TODAY Sports

Serena Williams of the USA reacts against Bianca Andreescu of Canada in the women’s final match on day thirteen of the 2019 U.S. Open tennis tournament at USTA Billie Jean King National Tennis Center. Mandatory Credit: Robert Deutsch-USA TODAY Sports

Serena Williams of the USA hits to Bianca Andreescu of Canada in the women’s final match on day thirteen of the 2019 U.S. Open tennis tournament at USTA Billie Jean King National Tennis Center. Mandatory Credit: Robert Deutsch-USA TODAY Sports

Bianca Andreescu of Canada (right) and Serena Williams of the United States (left) hug each other during the trophy presentation after the women's singles final on day thirteen of the 2019 US Open tennis tournament at USTA Billie Jean King National Tennis Center. Mandatory Credit: Danielle Parhizkaran-USA TODAY Sports

Serena Williams of the USA reacts after winning a point against Bianca Andreescu of Canada in the women’s final match on day thirteen of the 2019 U.S. Open tennis tournament at USTA Billie Jean King National Tennis Center. Mandatory Credit: Robert Deutsch-USA TODAY Sports

U.S. Open winner Bianca Andreescu poses with her trophy at top of the Rock in New York, U.S., September 8, 2019, in this screen grab obtained from a video. Reuters TV via REUTERS TPX IMAGES OF THE DAY.

Bianca Andreescu of Canada celebrates match point against Serena Williams of the United States in the women's singles final on day thirteen of the 2019 US Open tennis tournament at USTA Billie Jean King National Tennis Center. Mandatory Credit: Robert Deutsch-USA TODAY Sports

Serena Williams of the United States returns a shot against Bianca Andreescu of Canada in the women's singles final on day thirteen of the 2019 US Open tennis tournament at USTA Billie Jean King National Tennis Center. Mandatory Credit: Danielle Parhizkaran-USA TODAY Sports

Bianca Andreescu of Canada hits to Serena Williams of the USA in the women’s final match on day thirteen of the 2019 U.S. Open tennis tournament at USTA Billie Jean King National Tennis Center. Mandatory Credit: Robert Deutsch-USA TODAY Sports

Bianca Andreescu of Canada celebrates match point against Serena Williams of the United States in the women's singles final on day thirteen of the 2019 US Open tennis tournament at USTA Billie Jean King National Tennis Center. Mandatory Credit: Robert Deutsch-USA TODAY Sports

Bianca Andreescu of Canada (left) greets Serena Williams of the USA after the women’s singles final on day thirteen of the 2019 U.S. Open tennis tournament at USTA Billie Jean King National Tennis Center. Mandatory Credit: Robert Deutsch-USA TODAY Sports

Serena Williams of the USA acknowledges the crowd in the trophy ceremony with Bianca Andreescu of Canada after the women’s singles final on day thirteen of the 2019 U.S. Open tennis tournament at USTA Billie Jean King National Tennis Center. Mandatory Credit: Robert Deutsch-USA TODAY Sports TPX IMAGES OF THE DAY

Serena Williams of the USA serves to Bianca Andreescu of Canada in the women’s final match on day thirteen of the 2019 U.S. Open tennis tournament at USTA Billie Jean King National Tennis Center. Mandatory Credit: Robert Deutsch-USA TODAY Sports

Bianca Andreescu of Canada hits a backhand against Serena Williams of the United States (not pictured) in the women?s final on day thirteen of the 2019 US Open tennis tournament at USTA Billie Jean King National Tennis Center. Mandatory Credit: Geoff Burke-USA TODAY Sports

Serena Williams of the USA reacts after a miss to Bianca Andreescu of Canada in the women’s final match on day thirteen of the 2019 U.S. Open tennis tournament at USTA Billie Jean King National Tennis Center. Mandatory Credit: Robert Deutsch-USA TODAY Sports

Bianca Andreescu of Canada celebrates match point against Serena Williams of the United States in the women's singles final on day thirteen of the 2019 US Open tennis tournament at USTA Billie Jean King National Tennis Center. Mandatory Credit: Robert Deutsch-USA TODAY Sports

Bianca Andreescu of Canada with the US Open championship trophy after beating Serena Williams of the USA in the women’s singles final on day thirteen of the 2019 U.S. Open tennis tournament at USTA Billie Jean King National Tennis Center. Mandatory Credit: Robert Deutsch-USA TODAY Sports TPX IMAGES OF THE DAY

Serena Williams of the USA serves to Bianca Andreescu of Canada in the women’s final match on day thirteen of the 2019 U.S. Open tennis tournament at USTA Billie Jean King National Tennis Center. Mandatory Credit: Robert Deutsch-USA TODAY Sports