Top seed and defending champion Jelena Dokic was knocked out in the first round of the WTA Sarasota Open claycourt tournament.
The 19-year-old Yugoslavian was eliminated 6-3 6-3 by Argentina's Paola Suarez.
Dokic looked to have returned to form at the Nasdaq-100 Open in Miami last week when she reached the quarter-finals - the only time this year that she won three matches in a row.
But her inconsistency returned against Suarez and she was easily beaten.
Last year's runner-up, eighth seed Tatiana Panova of Russia, also crashed out.
She also lost in straight sets to Iroda Tulyaganova of Uzbekistan 6-3 7-5.
And fourth seed Ai Sugiyama of Japan also lost, 6-2 7-5, to veteran Conchita Martinez of Spain.
But second seed Anastasia Myskina of Russia snapped a three-match losing streak to record a 6-0 6-3 rout of Emilie Loit of France.
Anna Kournikova's miserable run of form continued as she went out 6-4 4-6 6-4 to Iva Majoli.
PA