Caroline Wozniacki regained the No. 1 ranking after beating Shahar Peer of Israel to reach the semifinals of the Dubai Championships on Friday.
The 20-year-old Dane lost the top spot Monday to Kim Clijsters , but will officially reclaim it when the new rankings are released next week.
Wozniacki next meets former No. 1 Jelena Jankovic, who beat fourth-seeded Australian Samantha Stosur 6-3, 5-7, 7-6 (4).
''Of course, it's nice to be back to No. 1,'' Wozniacki said after her 6-2, 6-4 win over Peer. ''It's a good feeling. I gave Kim one week. Hopefully, now I will have it for a few more weeks.''
On her Twitter page, Wozniacki highlighted her return to No. 1 which prompted Clijsters to tweet in reply: ''Congrats :-) ha ha.''
Wozniacki first rose to the top in October, replacing the injured Serena Williams, but she has yet to reach a Grand Slam final. She lost to Li Na of China in the Australian Open semifinals in January.
However, she was among the most consistent players in 2010. She won the most tournaments and appears in good form in Dubai, easily beating an ailing Anna Chakvetadze and then dropping only one game in her third-round match against Japanese qualifier Ayumi Morita.
''I'm playing good tennis,'' Wozniacki said. ''I feel when I'm playing on a high level, I'm tough to beat. So, I'm really pleased about the way I'm playing at the moment.''
Her win Friday ended another strong run from Peer, who two years ago was barred from playing in Dubai because of nationality. The Israeli player is still given extra security and isolated from the other players in a guarded compound.
Last year, Peer reached the semifinals - beating Wozniacki on the way.
This time, Wozniacki went up 3-0 in the first set and was never seriously challenged mostly due to the erratic play of the Israeli who had 34 unforced errors - more than twice that of the Dane. Wozniacki went up 4-0 in the second set, and closed out the match with an overhead smash.
''I played two games good in the first set and only last three or four games in second set. Between that, I played pretty terrible,'' Peer said. ''I don't think she had to do anything, just be there and put the balls in. I finished much better than I started.''
