Coco Gauff has won her first Grand Slam title at age 19 by coming back to defeat Aryna Sabalenka 2-6, 6-3, 6-2 in the U.S. Open final. Gauff was spurred on Saturday by a raucous partisan crowd that was loud from start to finish. Gauff is the first American teenager to win the country’s major tennis tournament since Serena Williams in 1999.