French seventh seed Benoit Paire was an early casualty at the Vienna Open as he slipped to defeat against Paolo Lorenzi.
Paire has enjoyed a solid season that has seen him break into the world's top 50, but he was below-par against Lorenzi as the Italian triumphed 6-4 6-4.
The only other seed in action on Tuesday also departed the tournament as Belgium's eighth seed Xavier Malisse was beaten 4-6 6-1 7-6 (8/6) by Slovenian qualifier Grega Zemlja.
Two more qualifiers also advanced, with Canada's Vasek Pospisil beating home favourite Andreas Haider-Maurer 3-6 7-6 (7/3) 6-1, and Germany's Daniel Brands overcoming Ruben Bemelmans of Belgium 6-7 (7-5) 6-4 6-3.
American Jesse Levine eased past Poland's Lukasz Kubot 6-3 6-4, Australia's Matthew Ebden was a 7-5 0-6 6-0 win over Filippo Volandri, while Slovenia's Aljaz Bedene went through after Guillermo Garcia-Lopez retired trailing 6-4 1-0.