Top seed Roger Federer suffered a shock 6-3 6-4 defeat by Germany's Daniel Brands in his opening match at his home Swiss Open on Thursday - the latest setback for the former world number one.
The 17-times grand-slam champion was beaten in 66 minutes by the 55th-ranked Brands in the second round in Gstaad, a week after beating the same player in the Hamburg tournament.
"It helped that I already played him in Hamburg last week," Brands said on the ATP website (www.atpworldtour.com).
"Of course you are very impressed when you face him on the court for the first time. It's completely different from what you see when you watch him on TV once you see him on the other side of the court."
Federer, 31, slipped out of the world's top four for the first time since 2003 following a shock defeat by journeyman Sergiy Stakhovsky at Wimbledon and last week lost in the Hamburg semi-finals to then 114th-ranked Argentine Federico Delbonis.
Losing in his own backyard will be particularly galling for Federer, who is now ranked fifth in the world and who recently switched to a larger-headed racket.
When he arrived at the tournament for the first time since winning it in 2004, Federer was presented with a cow named Desiree to mark 10 years since his first Wimbledon triumph.
Brands, who gave Rafael Nadal a scare in the French Open first round, was offering no gifts though as he saved all five break points he faced and served 11 aces.
Defeats against players ranked outside the top 10 used to be almost unheard of when Federer dominated men's tennis but they are now happening on a more regular basis.
Federer's only title this year came on grass at Halle and he has reached only one other final, losing to Nadal in Rome.
(Writing by Martyn Herman; Editing by Clare Fallon and Sonia Oxley)