After rain wreaked havoc in New York over the last two days, the women finally returned to the courts at the USTA Billie Jean King National Tennis Center for the first time since Monday.
The ninth-seeded Stosur beat the second-seeded Russian Zvonareva for an eighth straight time, as the Aussie posted a comprehensive 6-3, 6-3 victory in 67 minutes on the Grandstand court. Stosur fired 25 winners, compared to only nine for the Russian on Day 11, and Zvonareva was unable to break her big- serving Aussie counterpart.
Stosur was last year's French Open runner-up, while Zvonareva lost in last year's U.S. Open and Wimbledon finals. The Russian gave way to Belgian star Kim Clijsters in last year's lopsided finale in Flushing.
The 27-year-old Stosur will now appear in her third career Grand Slam semifinal and her first-ever U.S. Open semi.