In the past year, Karolina Pliskova, 24, has been in the top 10 and became the highest-ranked player from the Czech Republic.
But until Monday, she had never played in the fourth round of a Grand Slam tournament. She was the only player in the top 20 who had yet to reach the quarterfinals of a major.
Pliskova, the No. 10 seed, changed that at this year’s United States Open with her 4-6, 6-4, 7-6 (3) victory over the sixth-seeded Venus Williams in a 2-hour-24-minute battle at Arthur Ashe Stadium.
Pliskova rallied from a break down to take the second set, but in the third it was Williams’s turn to try for a comeback.