NEW YORK (AP)—American Irina Falconi followed up her first win at a Grand Slam tournament with a second, upsetting 14th-seeded Dominika Cibulkova on Wednesday to reach the third round of the U.S. Open.

Falconi ended the three-set victory with one of the best shots of the first week, running down the ball behind the umpire’s chair to somehow angle it across the net for a winner. Falconi won 2-6, 6-3, 7-5 at Arthur Ashe Stadium, a last-minute location change after Venus Williams withdrew, opening up a slot on center court.

The 21-year-old Falconi, ranked 79th, had never won a match in four Grand Slam appearances before her three-set win over 45th-ranked Klara Zakopalova on Monday. Falconi had been 0-3 against top-20 players.

Cibulkova, from Slovakia, was a semifinalist at the 2009 French Open.