Jelena Ostapenko apologized on social media Saturday for telling Taylor Townsend she had "no education" after losing to her at the U.S. Open earlier in the week.

U.S. Open opponents Taylor Townsend and Jelena Ostapenko got into a face-to-face argument on the Court 11 sideline right after Townsend won their second-round match 7-5, 6-1 on Wednesday.

Top seed Serena Williams, bidding for her sixth US Open crown, crushed Taylor Townsend 6-3, 6-1.

World No.1 Serena Williams could potentially play Wimbledon champion Petra Kvitova in the semifinals after the draw was held Thursday. Second-seeded Simona Halep and fourth-seeded Agnieszka Radwanska are in the other half. Halep could meet five-time major champ Maria Sharapova in the quarterfinals.