By DPA,
Auckland : Top seed Maria Sharapova put in a patchy but a successful effort Wednesday for a quarter-final place at the ASB Classic while second-seeded holder Yanina Wickmayer was stretched to three sets.
Three other seeds crashed out in the pre-Australian Open event.
Sharapova kept her New Zealand debut week alive as she beat Czech Renata Voracova 6-3, 7-5, while Belgian Wickmayer beat German Sabine Lisicki 6-2, 3-6, 6-2.
Outsider Romanian Simona Halep advanced as seventh-seeded Russian Elena Vesnina retired trailing 2-6, 6-4, 4-0. Hungarian Greta Arn beat Swedish eighth seed Sofia Arvidsson 4-6, 7-5, 7-5.
British teenager Heather Watson, ranked 176th, went past Spain’s Carla Suarez Navarro, seeded ninth, 7-6 (7-5), 6-1.
Sharapova faced a challenge in her second match of 2011 as she trailed 1-3 against Voracova in the opening set. But the three-time Grand Slam winner solved that problem by reeling off five straight winning games.
The Russian prevented the possibility of a third set as she won four more games on the trot to see off a challenge in the second set and close out the win in one hour, 40 minutes despite nine double-faults.
Sharapova booked the last eight berth against Arn, the number 88.
“A little bit sloppy, certainly a bit up and down. It was lucky I hung in there,” said 18th-ranked Sharapova.
“I did not serve that great especially in the second set. My toss was all over the place. In the second set it was up and down, I wasn’t doing much in order to hurt her.”