Kerber avoids Vandeweghe scare
Third seed Angelique Kerber survived a major scare to progress through to the quarter-finals of the Bank of the West Classic in Stanford at the expense of Coco Vandeweghe.
The momentum looked to be with Vandeweghe as the 22-year-old American recovered from losing a first-set tie-break to win all six games in the second set.
However, German Kerber battled back herself in the third set to take the victory 7-6 (7/4) 0-6 6-2 in two hours and eight minutes.
"The first set was very tough and very close, and I pulled it out in a tie-break," said Kerber on www.wtatennis.com.
"In the second set, I completely lost my rhythm, but I got it back in the third set. It was a tough opener for me, but I'm happy to be in the quarter-finals."
Kerber will now take on Garbine Muguruza - first-round conqueror of sixth seed Dominika Cibulkova - for a place in the semi-finals with the Spaniard defeating Slovakia's Daniela Hantuchova 6-4 6-4.
Fifth seed Ana Ivanovic had nowhere near as many problems as Kerber as the former French Open champion brushed aside Canadian qualifier Carol Zhao 6-1 6-1 in just 55 minutes.
Birthday girl Victoria Azarenka slumped to a fourth consecutive straight sets defeat to Venus Williams as the two former world No 1s went toe-to-toe for a place in the quarter-finals.
Williams took an hour and 42 minutes to emphatically seal the 6-4 7-6 (7/1) win on the day Azarenka turned 25 and set up a last-eight encounter with Andrea Petkovic.