Top-seeded Agnieszka Radwanska was an easy winner on Wednesday to advance to the quarterfinals of the ASB Classic tennis event.

Poland's Radwanska rolled past Romania's Simona Halep 6-3, 6-1 on the hardcourts at ASB Tennis Centre and will now face Elena Vesnina in the quarters after the Russian took a 6-2, 6-3 victory over sixth-seeded Yaroslava Shvedova of Kazakhstan.

Johanna Larsson of Sweden posted the big upset on Wednesday as she took down second-seeded German Julia Goerges 7-5, 6-7 (1-7), 6-3.

Yanina Wickmayer, the third seed out of Belgium, easily advanced on Wednesday in a 6-3, 6-0 pasting of Switzerland's Romina Oprandi, while eighth-seeded German Mona Barthel defeated Greece's Eleni Daniilidou 7-6 (8-6), 6-2.

In unseeded play, American Jamie Hampton defeated New Zealand's Marina Erakovic 6-1, 7-6 (7-5), Belgium's Kirsten Flipkens took a 6-2, 6-2 win over Pauline Parmentier of France, and Kiki Bertens of the Netherlands grabbed a 6-4, 3-6, 6-3 victory over Heather Watson of Great Britain.

This event serves as a tune-up for the Australian Open, which starts January 14.