Federer, Azarenka advance at Cincy

Defending men's champion and fifth-seeded Roger Federer advanced to the third round of the Western & Southern Open with a 6-3, 7-6 (7) win over 29th-ranked Philipp Kohlschreiber on Tuesday.

''It was just really important to play somewhat of a clean match,'' said Federer, who already has won a record five W&S championships and improved to 7-0 in his career against Kohlschreiber. ''Straight sets is always a good match. It's a good win for me.''

In earlier action on the women's side, second-ranked Victoria Azarenka held off an upset bid by qualifier Vania King to pull out a 6-1, 7-6 (6) win and advance to the third round. Azarenka rallied from a 3-0 hole in the second set to force the tiebreaker against the 140th-ranked American.

Azarenka, who has been bothered by a lower back injury, won her first match since losing to Samantha Stosur in the finals of the Southern California Open two weeks ago.

''I think the beginning of the second set wasn't very good for me,'' Azarenka said. ''There were quite a few unforced errors and just really fast mistakes, which didn't happen in the first set.''

Fourteenth-seeded Jelena Jankovic, the 2009 champion and 2011 runner-up, advanced to the second round with a 7-6 (5), 5-7, 6-2 win over Wimbledon finalist Sabine Lisiski.

Varvara Lepchenko of the United States advanced with a 6-2, 2-6, 6-2 win over Flavia Pennetta, and Jamie Hampton needed three sets to overcome Anastasia Pavlyuchenkova 7-5, 4-6, 6-3.

Alize Cornet rallied past Ana Ivanovic 2-6, 7-6 (8), 6-4.

Sorana Cirstea, the 21st-ranked Romanian who lost to No. 1 Serena Williams in the finals of the Rogers Cup in Toronto on Sunday, withdrew from her first-round match against Yanina Wickmayer.

Cirstea was replaced by No. 43 Monica Niculescu, who lost in this past weekend's qualifying but stayed around in case a spot opened up in the singles main draw and to play doubles. The Romanian capitalized on her second chance with a 6-1, 6-2 win over the 58th-ranked Wickmayer.

No. 10 seed Caroline Wozniacki easily advanced with a 6-1, 6-1 win over Shuai Peng.

In other men's matches, John Isner defeated Florian Mayer 6-3, 6-4, and Grigor Dimitrov defeated Brian Baker 6-3, 6-2. Third-seeded David Ferrer edged 102nd-ranked American Ryan Harrison 7-6 (5), 3-6, 6-4.

Gilles Simon was forced to retire because of a strained hip against Vasek Pospisil, who was leading 6-3, 1-1.