Venus Williams reached the third round at the US Tennis Open by defeating another American Bethanie Mattek-Sands 6-4 6-2.
The third seed wore heavy strapping around her left knee, an injury that almost saw her lose in the first round to Vera Dushevina.
But she was seldom troubled by an opponent who could not match her power and range.
Williams, who won back-to-back titles in New York in 2000 and 2001, will play Slovakia's Magdalena Rybarikova for a place in the last 16.
