Juan Martin Del Potro battled back from the brink of defeat to beat Daniel Brands and book his place in the Erste Open quarter-finals.
The Argentinian edged home 6-7 (7-5) 7-6 (7-4) 7-6 (7-5) in a three-hour match without a single break of serve, to claim a win which improves his hopes of reaching the ATP Tour finals in London.
Luxembourg's Gilles Muller joined Del Potro in the last eight as he upset home favourite and fourth seed Jurgen Melzer, shrugging off a lapse in the second set to record a 6-3 3-6 7-6 (7-4) success.
In first round action, American Donald Young beat fifth seeded Italian Fabio Fognini 7-6 (10-8) 6-3, while Austrian wild-card Dominic Thiem delighted the home fans with a 7-6 (7-3) 6-3 win over Slovakia's Lukasz Lacko.
