NEW YORK (AP) _ Justine Henin regained the No. 1 ranking on Monday and will head into this week's Sony Ericsson Open in Miami as the favourite.

Russian Maria Sharapova would have stayed No. 1 if she'd reached the semifinals in defence of her Pacific Life Open title at Indian Wells last week, but the 19-year-old Russian fell in the fourth round.

Henin was poised to take over after winning successive titles in the Middle East in Dubai, U.A.E., and Doha, Qatar, before skipping Indian Wells.

The Belgian conceded the No. 1 ranking to Sharapova in January when she withdrew from the Australian Open in the midst of a divorce.

They swapped places again on Monday.

Henin first ascended to No. 1 in October 2003, but lost it after a week. In November that year she was back on top and remained there until September 2004. After more than two years, she was No. 1 again after winning the season-ending WTA Championships last November.

Her fourth stint on top ensured she will surpass American Serena Williams' tally of 57 weeks at the top during the Sony Ericsson Open, and rank seventh all-time since the WTA Tour rankings began in 1975.

Also in Monday's rankings, Indian Wells runner-up Svetlana Kuznetsova reached a career-high No. 3. The former U.S. Open champion will defend her title in Miami. The rest of the top 10 was Amelie Mauresmo, Kim Clijsters, Martina Hingis, Nadia Petrova, Nicole Vaidisova at a career-best No. 8, Jelena Jankovic, and Elena Dementieva.

Second-time Indian Wells champ Daniela Hantuchova, a former No. 5, improved from No. 18 to No. 12.