WASHINGTON (AP) — Andrea Petkovic upset No. 6-seeded Mona Barthel 6-2, 6-2 in the second round of the Citi Open on Wednesday.
No. 64-ranked Barthel will play the winner of No. 79-ranked Paula Ormaechea and No. 88-ranked Olga Puchkova, who advanced by beating No. 15-ranked Sloane Stephens. Barthel is ranked No. 33, and her loss guarantees at least one quarterfinal between unseeded players.