Third seed Sabine Lisicki posted a first- round win Tuesday at the $235,000 U.S. National Indoor Tennis Championships.

The oft-injured German slugger doused promising American Madison Keys 7-5, 6-3 on the hardcourts at The Racquet Club of Memphis. Lisicki will face Hungarian Melinda Czink in the round of 16 on Wednesday.

Seventh seed Magdalena Rybarikova reached the quarterfinals by besting American Lauren Davis 7-6 (7-2), 6-2 in a second-round affair, while Jamie Hampton made short work of Coco Vandeweghe, needing 71 minutes to post a 6-3, 6-0 decision in the other second-round tilt.

Two other opening-round results saw French qualifier Claire Feuerstein upend fifth-seeded Czech Lucie Hradecka 6-3, 6-4 and Czech Andrea Hlavackova vanquish American Melanie Oudin 6-4, 3-6, 6-3.