GSTAAD, Switzerland (AP) Third-seeded Janko Tipsarevic was upset by Robin Haase 6-2, 6-2 Thursday at the Swiss Open.
Tipsarevic had six double-faults in the second-round loss.
Two former Swiss Open champions advanced to the quarterfinals.
Marcel Granollers, the 2011 winner, beat Federico Delbonis 6-2, 7-5, and 2008 champion Victor Hanescu led Roberto Bautista 7-6 (2), 3-2 when the Spaniard retired with a back injury.
Top-seeded Roger Federer will play his first match in Gstaad since 2004, when he faces 55th-ranked Daniel Brands at the clay-court event.
Federer beat Brands last week in the second round in Hamburg, Germany.