Updated

Rising American Jamie Hampton stunned top-seeded world No. 4 Agnieszka Radwanska Tuesday at the $690,000 Aegon International tennis event, a final grass-court Wimbledon tune-up.

The 23-year-old qualifier Hampton doused last year's Wimbledon runner-up and the 2008 Eastbourne titlist Radwanska 7-6 (7-2), 6-2 at Devonshire Park.

Four other top-five seeds avoided upsets, as second-seeded Aussie Open runner- up Li Na handled France's Alize Cornet 6-2, 6-4; third-seeded Angelique Kerber topped Romanian Sorana Cirstea 6-4, 6-4; fourth-seeded 2011 Wimbledon champ Petra Kvitova dropped Romanian Monica Niculescu 6-4, 6-1; and fifth-seeded former world No. 1 Caroline Wozniacki was leading defending Eastbourne champion Tamira Paszek 6-2, 2-2 when the Austrian retired on Day 2.

Paszek upset Kerber in last year's finale here.

Another upset came when wild card and former U.S. Open champion Sam Stosur eliminated eighth-seeded Russian Nadia Petrova 6-2, 6-3.

Several other women notched opening-round wins, including wild card Elena Baltacha and her fellow Brit Laura Robson and 2010 Eastbourne champ Ekaterina Makarova.

On Wednesday, second-round matches will come for Li, Kerber, the 2011 Eastbourne runner-up Kvitova, and Wozniacki. Li will take on former Wimbledon runner-up Marion Bartoli, while the 2009 Eastbourne winner Wozniacki will battle the crowd favorite Robson. Bartoli was the Eastbourne champion two years ago.