The 20-year-old Serb dislodged Russia's Maria Sharapova from the top when she defeated compatriot Jelena Jankovic to reach the final of the French Open on Thursday.

"Being number one is a dream come true for me," said Ivanovic, who will face Russian Dinara Safina in the Roland Garros showpiece on Saturday.

"It was a big surprise because I was so focused on the tournament. This is a great achievement and something that I'm very proud of. It hasn't exactly hit me yet because it won't be official until Monday. I'm sure we'll have a big celebration then."

Ivanovic had been in a four-way race with Jankovic and Russians Sharapova and Svetlana Kuznetsova to secure the top spot at the end of the claycourt grand slam.

But the defeats of her three main rivals before Saturday's final means Ivanovic clinched the ranking early.

Sharapova's latest stint at the top spot would have lasted for only three weeks as she took over as world number one after Justine Henin requested to be removed from the standings following her retirement last month.

The Serbian is the 17th player to claim the top spot since its inception in the mid 1970s.

"We have all witnessed the dramatic rise in Serbian tennis during the last few years and on Monday that will reach a new pinnacle when Ana Ivanovic is recognised as the WTA Tour's new number one player," WTA Tour chief Larry Scott said in a statement.

"Ana is both a remarkable player and person, and no doubt the best is still yet to come in her still young career. It is inspiring to see Ana's years of hard work and determination being rewarded."