It was Hingis' first match on home soil and her first appearance at the tournament in six years.

``I'm returning defending champion,'' Hingis joked. ``There were a lot of people that I know and friends who came to see the match. It's always special to play in front of a home crowd.''

The 26-year-old Swiss player reached the Zurich final in 1996 and '99 and won in 2000, but has been absent since. She was injured in 2001 and '02, and retired in early '03.

Hingis wrapped up the first set in 21 minutes. But trailing 3-0 in the second set, the hard-hitting Groenefeld raised her play and swept the next three games. Then, on serve at 5-4, Hingis squandered two match points.

But the former top-ranked player broke Groenefeld in the 12th game and won with a match point to spare.

``I don't think she gave it away (in the first set). I made her give it to me,'' Hingis said.

Katarina Srebotnik of Slovenia was scheduled to face Mary Pierce later, and Anna Chakvetadze, who beat Nadia Petrova to win the Kremlin Cup last weekend, withdrew from the event. Tournament organizers said they had not yet received an explanation for the Russian's withdrawal Monday.

Hingis, who still needs to secure a berth for the season-ending WTA Championship next month, is seeking her third WTA title since returning from a three-year retirement.

Zurich is the last big event before the WTA Championship in Madrid, Spain. Only the top eight players in the WTA race rankings qualify for the tournament, and Hingis is currently in eighth place.

The top three seeds in Zurich _ Amelie Mauresmo, Maria Sharapova and Svetlana Kuznetsova _ already have qualified, but fourth-seeded Elena Dementieva, sixth-seeded Patty Schnyder and Nicole Vaidisova are still vying for spots.