The seventh-seeded Zheng is through to the quarterfinals after defeating Croatian Donna Vekic 7–6 (7–2), 4–6, 6–2 – a much tougher match than the Olympic Games final a month ago, which Zheng also won over Vekic.
I'm really proud of myself because it's not easy to switch surfaces from clay to hard, especially since I went home to China and didn't get as much training as the others, says Zheng.
So I'm just trying to find a way to win matches even if I don't feel on top.
The match took almost three hours (2.50) and became the women's match that finished latest at night on Flushing Meadows in US Open history.
Olympic champion Zheng faces second-seeded Belarusian Aryna Zabalenka in the quarterfinals, where she hopes to get revenge from the Australian Open final in January. They also met on Flushing Meadows last year, when Zabalenka also won.