WARSAW, May 1: Nadia Petrova struggled to overcome unranked Polish junior Katarzyna Piter before reaching the second round of the Warsaw Cup on Monday.

The fifth-seeded Russian, who last year took three clay-court titles leading up to the French Open, only to injure her hip and miss both Roland Garros and Wimbledon, eventually claimed a 6-3, 7-5 victory.

She failed to serve out the match after breaking to lead the second set 5-4. Piter played well defensively, hit some good passing shots and led the second set 2-0 before Petrova levelled.

Sixth-seeded Russian Anna Chakvetadze had an even more difficult time in overcoming American Jill Craybas, taking just six minutes short of two hours to secure a 7-6, 7-5 victory.

Both players failed to find consistency in the cold and damp conditions, with Chakvetadze failing to serve out the first set at 5-4 and needing three set points to claim the tiebreak.

In the second set, a frustrated Chakvetadze was unable to convert any of four break points at 4-3 that would have left her serving for the match, and she then dropped her own serve to fall behind 5-4.

This time it was Craybas who was unable to take advantage of a leading position and Chakvetadze went on to win the final three games of the match.

Eighth seeded Slovenian Katarina Srebotnik slumped to a 6-3, 4-6, 6-1 defeat against Alona Bondarenko of Ukraine and Italian Mara Santangelo overcame Severine Bremond of France 6-2, 6-3.

Defending champion Kim Clijsters, playing her only clay court tournament of the year, is seeded two behind fellow Belgian Justine Henin. Three-times runner-up Svetlana Kuznetsova of Russia is seeded three, with Serbian Jelena Jankovic seeded four.

American Venus Williams, champion in 2004, is unseeded and could clash with seventh seed Elena Dementieva of Russia in the second round.

Monday’s results (prefix number denotes seeding):

First round: Alona Bondarenko (Ukraine) beat 8-Katarina Srebotnik

(Slovenia) 6-3, 4-6, 6-1; 5-Nadia Petrova (Russia) beat Katarzyna Piter (Poland) 6-3, 7-5; 6-Anna Chakvetadze (Russia) beat Jill Craybas (US) 7-6 (8-6), 7-5; Mara Santangelo (Italy) beat Severine Bremond (France) 6-2, 6-3.—Reuters