Auckland - Venus Williams survived an error-strewn performance to reach the quarter-finals of the ASB Classic with a tense three-set win over Austrian Yvonne Meusburger Wednesday.
In the rain-disrupted match, the 33-year-old Williams was broken twice early as she dropped the first set 4-6 before rallying to win the next two 6-3, 6-2.
She next faces Spaniard Garbine Muguruza who dropped the first set against Canadian qualifier Sharon Fichman before recovering to win 1-6, 6-3, 6-3.
But Williams, who also struggled against Czech wildcard Andrea Hlavackova in the first round, said she would not adopt a conservative approach just to win points.
"If I stop being aggressive and start playing her game, that's when I'm really in trouble," she said.
"So it's better for me to get it out of my system and they start landing, than for me to push back and not move forward."
Although former world number one Williams has struggled in Auckland, and her world ranking has slipped to 47, fifth seed and fellow American Jamie Hampton said she remained a threat.
"The top half of the draw has fallen apart, but also you've got the unseeded Venus Williams which is a bit of a tough one," said Hampton, the only seeded player left in her half of the draw.
Hampton, who qualified for the quarter finals with a straight forward 6-3, 6-4 win over Kristyna Pliskova, is ranked 28th in the world but sees advantages in not being under the same spotlight as Williams.
"No one really know who I am so I can float under the radar a bit, but I'd like some exposure," she said.
Of the other seeded players in action on the third day, second seed Ana Ivanovic of Serbia cruised to a 6-1, 6-1 victory over Swede Johanna Larsson and third seed Kirsten Flipkens beat Karolina Pliskova, Kristyna's twin, 6-4, 6-3.
The Belgian raced to a 5-0 lead in the first set before losing concentration and dropping four straight games before regaining her rhythm.
Results from day three of the Auckland Classic tournament on Wednesday (x denotes seed):
Jamie Hampton (USA x5) bt Kristyna Pliskova (CZE) 6-3, 6-4
Garbine Muguruza (ESP) bt Sharon Fichman (CAN) 1-6, 6-3, 6-3
Venus Williams (USA) bt Yvonne Meusburger (AUT) 4-6, 6-3, 6-2
Sachie Ishizu (JPN) bt Julia Goerges (GER) 6-2, 3-6, 7-5
Kirsten Flipkens (BEL x3) bt Karolina Pliskova (CZE) 6-4, 6-3
Kurumi Nara (JPN) bt Ayumi Morita (JPN) 6-0, 6-1
Ana Ivanovic (SRB x2) bt Johanna Larsson (SWE) 6-1, 6-1