Williams has won three of the four tournaments she has played -- Gold Coast, Paris and Antwerp -- moving her within 137 points of No. 1 player Jennifer Capriati in this week's rankings.

The reigning Wimbledon and U.S. Open champion, Williams will become the new No. 1 regardless of her finish in the Dubai Women's Open this week.

Capriati, who was a runner-up at Oklahoma City last year, is not play in that tournament this week, allowing Williams to move ahead by at least five points in the rankings.

"I'm very excited about this achievement and look forward to building on it," said Williams. "Being No. 1 was firstly my parents' dream, but it soon became mine too, so reaching it was great not only for me, but for them too."

Williams follows Martina Hingis, Lindsay Davenport and Capriati as No. 1 players over the last four months.