College Park, Maryland: Second-seeded Nadia Petrova of Russia defeated Canada's Eugenie Bouchard 6-2, 6-2 in 52 minutes to advance to the quarterfinals of the Citi Open.
The 32nd ranked player in the world overpowered Bouchard by winning 19 of 22 first-serve points.
Petrova will next play fifth-seeded Bojana Jovanovski of Serbia, who held on to beat American Jill Craybas 6-4, 5-7, 6-4.
France's Virginie Razzano also booked a spot in the next round by upsetting sixth-seeded Elena Baltacha from Britain 6-4, 6-2. American Irina Falconi advanced after China's Zhang Shuai retired after the first set while trailing 6-4. Zhang played her second match in a 20-hour period and suffered from fatigue after win over fourth-seeded Jelena Dokic.
The second round resumes Thursday with top-seed Shahar Peer of Israel playing Russia's Alla Kudryavtseva.