Judges praised the 62-year-old not only for the duration of his 40 winks, but also for his volume, notching up snores of 70 decibels - around talking level.
The contest was run by Spain's National Association of Friends of the Siesta.
It was part of a campaign to revive the Spanish power-napping tradition, which is seen as threatened by the fast pace of modern life.
Over the course of nine days, 360 competitors were challenged to sleep for as much of a 20-minute period allotted to them as possible.
Participants stretched out on sofas in the Madrid shopping centre while their pulses were monitored to check they were asleep.
Judges awarded points for the speed with which participants fell asleep, the volume of their snoring, the most original sleeping position and the best-dressed sleeper.