A pair of former world No. 1s, including defending Birmingham champion Ana Ivanovic, exited the draw Wednesday at the Aegon Classic tennis event, a grass-court Wimbledon tune-up.
Portuguese qualifier Michelle Larcher de Brito knocked out the second-seeded Serb Ivanovic 6-4, 3-6, 7-6 (8-6), while Kazakhstan's Zarina Diyas advanced via walkover when 12th-seeded Victoria Azarenka withdrew from their scheduled second-round match, citing a left foot injury, at Edgbaston Priory Club.
"It's very disappointing for me to make this decision but I tried to practice and it just doesn't feel 100 percent," Azarenka said in a statement. "I don't think it's the best time for me to take a risk right now, especially right before Wimbledon, and I need to make sure I have the best preparation possible."
Ivanovic defeated Czech Barbora Strycova in last year's Birmingham finale.
Another high-profile player left the draw when France's Kristina Mladenovic drove out fifth-seeded 2014 Wimbledon runner-up Genie Bouchard of Canada 6-3, 4-6, 6-0.
Meanwhile, third-seeded Spaniard Carla Suarez Navarro held off Hungarian qualifier Timea Babos 6-2, 3-6, 6-4 and fourth-seeded German left-hander Angelique Kerber snuck past Bulgarian Tsvetana Pironkova 6-4, 2-6, 6-4.
Eighth-seeded former Wimbledon runner-up Sabine Lisicki set a new WTA single- match record by blasting 27 aces, as she topped Swiss teenager Belinda Bencic 6-1, 7-6 (7-4). Bencic was a grass-court runner-up in The Netherlands last week.
"It's nice to have another record!" the 2011 Birmingham titlist Lisicki said in her on-court interview. "It's obviously a good weapon to have on grass. And I love playing on grass, so it's nice to be back at the Aegon Classic Birmingham."
In other action involving seeds, a No. 10 Strycova beat fellow Czech Lucie Hradecka 6-3, 6-4; No. 13 Russian Svetlana Kuznetsova eased past Serbian qualifier Aleksandra Krunic 6-2, 6-1; No. 15 former top-ranked star Jelena Jankovic topped Aussie Casey Dellacqua 7-6 (13-11), 6-3; and Czech veteran Klara Koukalova doused No. 16 Frenchwoman Caroline Garcia 6-3, 6-0. Jankovic is a two-time winner here and two-time Aegon Classic runner-up.
Additional wins came for American Christina McHale and Slovaks Magdalena Rybarikova and Daniela Hantuchova, the 2013 Aegon champion and 2011 runner- up. Rybarikova titled here in 2009.
Sixth-seeded Czech Karolina Pliskova was leading British wild card Johanna Konta 3-6, 6-3, 4-3 when play was suspended for the day.
On Thursday, top-seeded Simona Halep will play a third-round match against the qualifier Koukalova.
The 2015 Aegon Classic titlist will earn $124,000.