Ayrton Senna's legend is complete now, but everyone's reputation has to start somewhere. In his case it probably started at the 1984 Race Of Champions.
The irony is, he should not have even been competing - he wasn't an F1 champion at that time, and had only competed in three F1 races. He was, however the reigning Formula 3 champion, although including him in a race with F1 household names was maybe stretching credibility a touch. However the organiser of the event, Gerd Kremer of Mercedes, knew Ayrton from his F3 days, and when Emmerson Fittipaldi declined to take part in the event due to commitments at Indianapolis, Kremer used his position to get Senna into the event.
Interestingly, this was also the start of the legendary rivalry - the first time Prost and Senna met. Prost actually picked Senna up from the airport and drove him 2 hours to the circuit, no doubt chatting a little on the way. For all that would come later between these two, it seems somehow fitting that they got to know each other sitting side by side in a car.
The saloon car race at the Nürburgring was meant to be a casual affair, a christening for the new Nurburgring F1 circuit; quite why the organisers thought this would be the case is not known, but the christening would soon turn into nothing less than a baptism of fire. Some of the greatest F1 drivers of all time, all in identical Mercedes 190E 2.3-16's, sounds like a recipe for nothing other than a four-wheeled version of a bare knuckle boxing match.
There were some incredible names competing that day - Prost, Alan Jones, John Surtees, Stirling Moss, Jack Brabham, Phil Hill, Denny Hulme, Niki Lauda, James Hunt, Keke Rosberg, Jodie Scheckter, John Watson, Klaus Ludwig and Manfred Schute, amongst others. Prost qualified on pole, only just edging out Senna. But when the race came, it was raining so the track was very wet; little did the other drivers know that thses were the sort of conditions that Senna excelled in. He quickly took the lead from Prost, albeit by forcing the Frenchman off the circuit; a portent of things to come and an incident that surely cast the die between these two. Senna then disappeared off into the distance, which to be fair was a feat probably made easier not all the drivers taking the event particularly seriously - especially James Hunt - but make no mistake Senna, thrashed everyone that day. He took the Mercedes by the scruff of the neck, squeezed every ounce of performance out of it and won the race ahead of Lauda.
It was an absolute driving masterclass by a young snot-nosed rookie that most of the drivers there had never even heard of; well they certainly remembered him afterwards. To quote Stirling Moss:
"From that moment he just continued to rise until he got to where he was only equalled, in my opinion, by Fangio".