Ninth-seeded Australian Samantha Stosur toppled world number two Vera Zvonareva 6-3, 6-3 to reach the semi-finals of the US Open on Thursday.
Stosur was untouchable on her serve, never facing a break point as she bundled last year's runner-up out in just 67 minutes.
In the semi-finals she'll face either 26th-seeded Italian Flavia Pennetta or unseeded German Angelique Kerber.