Russia's Dinara Safina returns the ball to Ukraine's Kateryna Bondarenko. (Lionel Cirroneau/Associated Press)

Russian tennis players Svetlana Kuznetsova and Dinara Safina advanced to the second round of the French Open on Tuesday before rain again disrupted play at Roland Garros.

The start of play was delayed by two hours, 50 minutes. The fourth-seeded Kuznetsova defeated Aiko Nakamura of Japan 6-2, 6-3 before the rain returned for about three more hours.

"I was first. I was lucky with that," said Kuznetsova, the 2004 U.S. Open champion. "I get in my match, so I have the rest of the day to relax, to take it easy, and tomorrow I practise and get prepared for my next match."

Safina, seeded 13th, defeated Kateryna Bondarenko of Ukraine 6-1, 6-3.

"I'm really happy that I could go through in two sets, especially before the rain started," said Safina, who missed the Italian Open with a back injury.

Amelie Mauresmo held her nerve and her serve when it counted Tuesday, reaching the second round by beating Olga Savchuk 7-5, 4-6, 6-1 in a match interrupted by rain.

Mauresmo, who missed the Italian and German Opens because of a rib injury, looked shaky much of her time on centre court.

"I had ups and downs, good things and some big mistakes, and that's also linked to very short preparation time," said Mauresmo, who won the Australian Open and Wimbledon in 2006.

Each of the first three days of the French Open have been affected by rain, but Tuesday's weather was the worst.with less than three hours of play the entire day. Only 13 matches were completed, five from the men's tournament and eight from the women's.

Three-time defending champion Rafael Nadal, who was originally scheduled to play his first match Monday, managed to play only two games against Thomaz Bellucci before rain suspended play for the day with the score 1-1.

To-seeded Maria Sharapova's match against Evgeniya Rodina never started, while Aleksandra Wozniak of Niagara Falls, Ont., was scheduled to play No. 20 Sybille Bammer of Austria but did not begin their match.

In other women's play, No. 14 Agnieszka Radwanska of Poland beat Mariya Koryttseva of Ukraine 6-4, 6-3.

In the men's tournament, No. 4 Nikolay Davydenko of Russia advanced by beating 2002 Australian Open champion Thomas Johansson of Sweden 6-3, 6-3, 6-3.

It led to the postponement of at least 20 matches, including top-seeded Maria Sharapova's encounter against fellow Russian Evgeniya Rodina.

Safina still has back pain

Despite the conditions around the grounds, Kuznetsova didn't appear to have any problems against the 71st-ranked Nakamura.

"I hit the ball big, but I also do hit heavy," Kuznetsova said.

"And when the ball with these conditions was very heavy, it was very comfortable for me.

"I was a bit weaker in the second set," the Russian added. "First few games I didn't play very well."

Nakamura has never reached the second round in four appearances at the French Open.

"I don't have pressure," Nakamura said about playing Kuznetsova. "A little bit nervous."

Safina, who was the last person to beat Justine Henin before the top-ranked Belgian retired from tennis this month, said she still had pain in her back.

"This is my weakest part of my body: the back," said Safina, the younger sister of two-time Grand Slam champion Marat Safin. "So I really had to go home and I had to take some care of it. I'm tall, so [I can't] always bend my knees, so I use really a lot [of] my lower back."