The former world men's tennis number one Thomas Muster lost in straight sets to a fellow Austrian little more than half his age as he returned to the ATP circuit after an 11-year absence.
23-year-old Andreas Haider-Maurer beat Muster in straight sets in front of a crowd of around 8,000 at the Vienna Open.
43-year-old Muster, who enjoyed an iron-man reputation during his heyday when he won the French Open in 1995, was given a wild card entry.
He is currently ranked 974th and began his comeback earlier this year on the Challenger Tour.
Muster became the first over-40 player to compete in the main draw of an ATP tournament since Jimmy Connors in the 1990s.
