Mikhail Youzhny collected only his third win on clay this season as he battled to overcome Jan-Lennard Struff at the Geneva Open.
Youzhny has been in poor form ahead of the tournament, but was able to hold his nerve in two tie-breaks to progress 7-6 (7-2) 7-6 (7-5), setting up a second-round meeting with Santiago Giraldo.
A tight opening set saw 12 holds of serve before the eighth seed was able to claim two mini-breaks to move ahead in the match.
Struff fought back and found a way through Youzhny's service game in the sixth, but the Russian broke back in the ninth game before converting his second match point in the breaker to progress.
Sixth seed Joao Sousa is also into round two after he beat Brazilian Joao Souza 7-5 6-3, but Marcos Baghdatis did not have such an easy day as he went out 6-7 (5-7) 6-3 6-3 to Thomaz Bellucci.
Having battled to take the opening set, seventh seed Baghdatis lost five out of six games in the second before being broken in the sixth game of the decider to give Bellucci victory.
Fifth seed Andreas Haider-Maurer was also dumped out by Russian qualifier Andrey Kuznetsov 6-2 6-4.
Meanwhile, there were straight-set wins for Jurgen Melzer and Albert Ramos over Damir Dzumhur and Marinko Matosevic respectively.