Maria Sharapova managed a win over Victoria Azarenka in the second round of the WTA LA Women's Tennis Championships.

The 22-year-old, who recently returned to the tour following a 10-month absence due to a shoulder injury, secured her place in round three with a 6-7 (4/7) 6-4 6-2 triumph against her Belarusian opponent.

Sharapova's fellow Russian, top seed Dinara Safina, advanced to the third round with a 6-2 6-4 triumph over Slovakian Daniela Hantuchova.

Hantuchova's compatriot, seventh seed Dominika Cibulkova, was another seeded casualty on Wednesday with Poland's Urszula Radwanska sealing a 6-4 6-7 (6/8) 6-4 victory.

Caroline Wozniacki, the fourth-seeded Dane, was also knocked out of the tournament, falling 1-6 6-4 7-6 (7/5) to Sorana Cirstea of Romania.

Radwanska's older sister, eighth seed Agnieszka, conceded only three games en route to a convincing 6-2 6-1 win over Japan's Ai Sugiyama

Fifth seed Nadia Petrova of Russia was pegged back in the second set but eventually prevailed 6-4 2-6 6-3 against Israeli Shahar Peer.

In other matches, there were straight-sets triumphs for 10th seed Flavia Pennetta of Italy, 13th-seeded Australian Samantha Stosur and 17th seed Sabine Lisicki of Germany.

Chinese duo Li Na and Jie Zheng, seeded 12th and 14th, each advanced in three sets - at the expense of Canada's Aleksandra Wozniak and Russian Elena Vesnina respectively.

Russia's Anna Chakvetadze, Belgian Yanina Wickmayer and Ukraine's Alona Bondarenko also battled through to round three.