KITZBUEHEL, Austria -- Leonardo Mayer of Argentina upset top-seeded Philipp Kohlschreiber 6-4, 7-6 (4) on Tuesday to reach the quarterfinals of the bet-at-home Cup.

Two-time champion Robin Haase started his title defense by defeating Guillaume Rufin of France 6-4, 7-6 (4) in the first round. The 68th-ranked Dutchman finished with 10 aces.

Haase, who won the event in 2011 and `12 and reached his third career final in Gstaad last weekend, will next play Daniel Brands. The German beat fifth-seeded Carlos Berlocq of Argentina 7-6 (4), 2-6, 6-2.

Victor Hanescu of Romania defeated Aljaz Bedene of Slovenia 6-2, 6-1, and Jan Hajek of Czech Republic beat Aldin Setkic of Bosnia 6-2, 6-1. Andreas Haider-Maurer beat fellow Austrian Dennis Novak 6-4, 6-4, and Guillermo Garcia-Lopez of Spain rallied to beat Thomaz Bellucci of Brazil 6-7 (1), 6-3, 7-6 (4).