To put her win into perspective, Williams had already won four of her seven major titles by the time Gauff was born, according to ESPN.
It isn't the first time Gauff has made tennis history in a major tournament. Earlier this year, she became the youngest female player to win a Grand Slam match in the qualifying rounds of French Open.
Gauff was born in Atlanta on March 13, 2004. She grew up in metro Atlanta before her family moved to Florida for her training.