Premise: The 8th Race of Champions was a non-Championship motor race, run to Formula One rules, held on 18 March 1973 at Brands Hatch circuit in Kent, UK. The race included several entrants in Formula 5000 cars and was won by Peter Gethin in a Chevron-Chevrolet B24 '72-05'. This was the only race other than the poorly-attended 1969 Madrid Grand Prix in which a Formula 5000 car beat a Formula One car.
Hypothesis: There has been one or more five year period in at least one of the last three centuries where a Formula One car has been bested by a Formula 5000 car.