Roger Federer failed to enjoy any home comforts at the Credit Agricole Suisse Open, losing 6-3 6-4 to Daniel Brands in the second round in Gstaad.
The big-hitting German hammered down six aces to take the first set in just 28 minutes and then quickly went a break up at the start of the second.
Federer took four games in a row, despite having to save four break points during that stretch, as he looked to battle back and gain a repeat of his three-set victory over the same opponent in Hamburg last week.
However Brands refused to be beaten this time, another barrage of aces helping finally seal his place in the last eight of the tournament. Although he failed with two match points, the third went the way of the world no 55.
Such an early exit is a further blow for the struggling Swiss - the 31-year-old was beaten by Argentine qualifier Federico Delbonis in the semi-finals in Germany and has won just one title, in Halle, so far this season.
"This is a really special win," said Brands. "I played at 100 per cent, I didn't have a big strategy, I just played point after point and tried to stay strong mentally."
Meanwhile, Robin Haase needed a little over an hour to beat third seed Janko Tipsarevic 6-2 6-2 and reach the quarter-finals.
The Dutchman was dominant on his first serve while racing to a 6-2 5-1 lead against Serbia's Tipsarevic but the former US Open quarter-finalist at least responded to survive four match points and force another game.
Haase soon completed the win and he will face Marcel Granollers in the last eight. The Spaniard saw off surprise German Open finalist Delbonis 6-2 7-5.
Victor Hanescu enjoyed an easy passage through to the next round after Roberto Bautista Agut retired hurt.
Romanian Hanescu, who was leading eighth-seeded Bautista Agut 7-6 (7/2) 3-2 when the Spaniard failed to recover from a medical time-out, will take on Brands next.