Australia's Jelena Dokic booked her spot in the second round of the Unicef Open on Tuesday, but top seed Kim Clijsters was knocked out by a qualifier.
Dokic was ruthless in the opening set against Russian Alla Kudryavtseva before eventually sealing the match 6-0 6-4 in just over an hour.
She will now face fourth seed Flavia Pennetta in the second round.
But the story of the day in 's-Hertogenbosch was Clijsters' surprising straight sets loss to Italian qualifier Romina Oprandi.
Oprandi defeated the world No.2 Belgian 7-6 (7-5) 6-3 in one hour and 33 minutes at the WTA/ATP joint event.
Clijsters looked out of sorts throughout the match, making a host of uncharacteristic unforced errors as she slumped to a defeat just three weeks after she was bundled out of the French Open in the second round.
Oprandi's reward for staging the upset is a third-round meeting with Japanese veteran Kimiko Date-Krumm, who defeated Spaniard Lourdes Dominguez-Lino 7-6 (7-3) 6-0.
In Tuesday's first-round matches, Australian Swede Johanna Larsson defeated Rebecca Marino of Canada 7-5 7-5, while Italian Sara Errani ended the participation of Dutch wildcard Kiki Bertens with a 7-6 (8-6) 6-1 victory.
Next up for Errani is a second-round match with Russian second seed Svetlana Kuznetsova, while Larsson will meet Belgian Kirsten Flipkens.