(CNN) -- Third seed Venus Williams stepped up her bid for her third U.S. Open title with a convincing 6-4 6-2 win over fellow American Bethanie Mattek-Sands on Wednesday.
Perfect in pink. Venus breezed through into the third round at Flushing Meadows.
Williams was on the brink of defeat against her first round opponent Vera Dushevina of Russia, but cut out the unforced errors in her second match at Flushing Meadows.
She will be joined in the third round by her sister, the second seed and pre-tournament favorite Serena, who cruised past Hungary's Melinda Czink 6-1 6-1.
There was disappointment for former world number one Amelie Mauresmo of France as she bowed out of the hardcourt grand slam.
The 17th seed was brushed aside 6-4 6-0 by Aleksandra Wozniak of Canada in their second round match.
But another former world number one, Kim Clijsters of Belgian, continued her fine run on her grand slam comeback.
She came from a set down to beat 14th seed Marion Bartoli of France 5-7 6-1 6-2 to reach the third round.
Clijsters, who won the U.S. Open in 2005, will play compatriot Kirsten Flipkens for a place in the last 16.
Also impressive was dangerous outsider Flavia Pennetta of Italy as the improving 10th seed whitewashed Sania Mirza of India 6-0 6-0.
In other matches 15th seed Sam Stosur had a surprise early exit after losing in straight sets to American Vania King, the world number 114.
Elsewhere, eighth seed Victoria Azarenka from Belarus eased past Czech Barbora Zahlavova Strycova in straight sets, while Russian Maria Kirilenko defeated 12th seed Agnieszka Radwanska 6-4 2-6 6-4. Fellow Russian Vera Zvonareva recovered after dropping a set to triumph over her compatriot Anna Chakvetadze.
Williams, who was playing with a heavily-taped left leg, showed few signs of the injury which troubled her against Dushevina, and gained an early break against the 124th-ranked opponent.
Mattek-Sands broke back but Williams duly gained a second break and served out the first set in 48 minutes.
The writing was on the wall for Mattek-Sands as she quickly fell a break down in second set and she could never get back on level terms against the heavy service of the seven-time grand slam winner.
A second break sealed her fate and despite facing three break back points in the final game, Williams served out for victory in one hour 31 minutes.
Awaiting her in the last 32 is world number 46 Magdalena Rybarikova of Slovakia, who defeated Chang Kai-Chen in three sets.