's-Hertogenbosch, The Netherlands (Sports Network) - Flavia Pennetta and Kim Clijsters were among Sunday's first-round winners at the $220,000 UNICEF Open, a final tine-up for Wimbledon.

The fourth-seeded Pennetta of Italy beat Olga Govortsova of Belarus 2-6, 6-1, 6-1 on the grass courts at Autotron Rosmalen.

Clijsters returned to action with a 6-7 (5-7), 6-2, 6-3 win over Romina Oprandi of Switzerland. The former world No. 1 missed the clay court season with a hip injury.

Anabel Medina Garrigues of Spain defeated Simona Halep of Romania 7-6 (7-3), 6-2.

Italian Roberta Vinci topped Aussie Jelena Dokic in last year's finale here.

The 2012 UNICEF champion will collect $37,000.