Czech Jan Mertl won his first ATP World Tour main-draw match on Monday, at the age of 34.
Mertl, the world number 306, beat fellow qualifier Yann Marti 6-4 6-7 (5-7) 6-2 in the Swiss Open Gstaad and will now face top seed Feliciano Lopez.
There were also first-round wins on the clay in Gstaad for 2013 champion Mikhail Youzhny, Elias Ymer and another qualifier, Thiago Monteiro, who represents the next opposition for second seed Gilles Simon.
Seventh seed Inigo Cervantes was eliminated from the Generali Open in Kitzbuhel, courtesy of a straight-sets loss to fellow Spaniard Daniel Gimeno-Traver.
Rising star Karen Khachanov beat Filippo Volandri 6-2 6-4 to set up a meeting with reigning champion Philipp Kohlschreiber. Daniel Munoz de la Nava, Igor Sijsling and Mischa Zverev were the others to reach round two in Austria on Monday.
In Umag, Aljaz Bedene was dumped out of the Croatia Open by Nikola Cacic, a player ranked 692 places below the Briton in the rankings.
World number 761 Cacic came from a set down to beat Bedene 5-7 6-4 6-4, while Leonardo Mayer overcame home favourite Nikola Mektic 7-5 6-2.