(photo credit: AP [file])
Shahar Pe'er will face Francesca Schiavone in the second round of the Rogers Cup in Toronto after defeating Monica Niculescu 6-4, 4-6, 7-6 (4) in a marathon three-hour first-round match on Tuesday.
The 21-year-old Israeli, who dropped to No. 68 in the world rankings on Monday, hasn't won two straight matches in over a month and will have to be at her best to do so with a victory over Schiavone (ranked 27th).
The Italian beat No. 15 seed Amelie Mauresmo 6-2, 3-6, 6-1 in the Frenchwoman's first match since Wimbledon.
Meanwhile, Maria Sharapova looked impressive in a 6-3, 6-4 win over 10th-seeded Nadia Petrova in the first round on Monday.
Sharapova broke Petrova once in the first set and twice more in the second to run her record to eight wins and one loss against her fellow Russian opponent.
No. 13 seed Marion Bartoli was also eliminated with a 6-4, 6-3 loss to Alona Bondarenko, who is ranked 33rd.
In late afternoon action from Toronto, third-ranked Venus Williams was upset 1-6, 7-5, 6-4 by Kataryna Bondarenko in the second round. Williams got off to a strong start but couldn't sustain it as she fell to 0-3 all-time at the tournament.
Bondarenko, ranked 64th, will face either Agnes Szavay or Agnieska Radwanska.
Earlier, 11th-ranked Ana Ivanovic rallied to a 2-6, 6-3, 6-2 triumph over Magdalena Rybarikova.
The 21-year-old Ivanovic, still seeking her first WTA Tour title of the season, overcame seven double-faults in the win over the 47th-ranked Rybarikova.
Ivanovic will play Lucie Safarova, who defeated Kaia Kanepi 6-4, 7-6 (3). Alla Kudryavtseva defeated Julie Coin 6-2, 1-6, 7-6 (6).
AP contributed to this report