This week's top-three seeds -- Agnieszka Radwanska, Petra Kvitova and Caroline Wozniacki -- all suffered opening-round upsets Tuesday at the Aegon International tennis event, a final Wimbledon tune-up.

Bulgarian grass-court specialist Tsvetana Pironkova doused the world No. 3 Radwanska 6-2, 6-4, while Russian Ekaterina Makarova stunned the fourth-ranked Kvitova 7-5, 6-4, and rising American Christina McHale took out the world No. 7 Wozniacki 6-1, 6-7 (7-9), 6-4 at Devonshire Park. The capable Makarova captured the title here two years ago.

"I think I have been playing a lot of matches this year, and I'm kind of like a little bit tired,'' said Radwanska, who double-faulted on match point against Pironkova. "Of course I was trying everything, but she's really playing good on grass."

Radwanska was the Eastbourne champion in 2008; Kvitova is the reigning Wimbledon champ and was last year's Eastbourne runner-up to France's Marion Bartoli; and the former No. 1 Wozniacki captured this tournament in 2009.

"It's not good preparation for Wimbledon, but I have more days for getting ready. I have to work hard now to improve my game," Kvitova said after losing to Makarova.

The reigning Eastbourne champ Bartoli avoided the Day-2 upset bug by leveling Romanian Sorana Cirstea 6-2, 6-2. Next up for the French slugger will be Canadian Aleksandra Wozniak on Wednesday.

In other action involving seeds, No. 5 German left-hander Angelique Kerber overcame Russian qualifier Elena Vesnina 3-6, 6-0, 7-5, No. 6 Czech Petra Cetkovska came back to beat lucky-loser and fellow countrywoman Andrea Hlavackova 3-6, 6-2, 6-1, and No. 7 Czech Lucie Safarova overcame Hungarian Timea Babos 3-6, 6-3, 7-6 (8-6).

Additional first-round wins came for Czech veteran Klara Zakopalova, Russian Anastasia Pavlyuchenkova, British qualifier Laura Robson and wild card Heather Watson, and Canadian qualifier Stephanie Dubois.

In some other second-round play on Wednesday, eighth-seeded Slovak Daniela Hantuchova, the 2004 Eastbourne runner-up, will face Austrian Tamira Paszek and McHale will take on her fellow 20-year-old Pavlyuchenkova.

The winner of this $637,000 tournament will collect $107,000.