Last year's finalist Robin Haase was forced to dig deep before advancing past Aleksandr Nedovyesov 6-4 6-7 (3/7) 6-3 in the first round of the Swiss Open.
The Dutchman, who lost to Russian Mikhail Youzhny in the final here 12 months ago, failed to close out his win in two sets against the 99th-ranked Nedovyesov, who beat him in Casablanca earlier this year.
Haase led a set and 5-4 when he was broken, with Kazakh Nedovyesov winning a tie-breaker to take the contest into a deciding set.
The seventh seed found his game just in time, though, breaking for 3-1 to earn the edge for eventual victory.
Also on Tuesday, two-time champion Thomaz Bellucci began his quest for a hat-trick with a victory over Austrian qualifier Gerald Melzer, brother of Jurgen, prevailing 6-3 6-4 in an hour and a quarter.
Kenny De Schepper of France beat Italy's Filippo Volandri 6-3 7-6 (7/3) while Blaz Rola of Slovenia stopped Brazilian Fabiano De Paula 6-4 6-4.