US Open 2019: Serena Williams reaches pre-quarterfinals
Williams beat Muchova 6-3, 6-2 after as she converted five out of nine break points against Karoliona Muchova.
Williams beat Muchova 6-3, 6-2 after as she converted five out of nine break points against Karoliona Muchova.
Serena will next face the winner of the other women's singles match between Dayana Yastremska and Karolina Muchova.
