Former world No.1 Kim Clijsters failed to maintain her impressive return as she slipped to a three-set defeat against Patty Schnyder at the BGL Luxembourg Open.
The Belgian, who marked her return from retirement with success at the US Open, was made to pay for a stuttering serve as Schnyder came through the second-round clash with a 6-4 3-6 7-6 (8-6) victory.
Clijsters was guilty of conceding 11 double faults, with Schnyder taking full advantage to set up a showdown with Sabine Lisicki in the next round.
"Patty played extremely smart. It's tough to force errors on her and break through her game," said Clijsters.
"I made more unforced errors and my first serve wasn't working the way I would have liked it to. I had my chances in the first set and I tried to fight through. It's disappointing when you're not playing your best."
Fourth seed Daniela Hantuchova was given a scare before coming through her clash with Lucie Hradecka.
Hantuchova finally saw off the brave challenge of her Czech opponent 7-5 3-6 6-2.
Hantuchova is joined in the next round by fifth seed Yanina Wickmayer and eighth-ranked Shahar Peer.
Wickmayer toppled Alize Cornet 7-5 7-6 (8-6), while Peer overcame Spain's Carla Suarez Navarro 3-6 6-3 6-1.
Katarina Srebotnik came back from a set down to beat Anne Kremer 2-6 6-4 6-0.
Clijsters 2010 Specials Win Specials: Clijsters to win 2+ Grand Slams 11/4
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