But, knowing if neither driver finished Senna would be crowned champion, the Brazilian forced Prost off the track at the first corner and cemented a second world title success.
He is McLaren's first world champion since Mika Hakkinen in 1999, and joins a club that includes his hero Ayrton Senna and all-time greats Alain Prost and Niki Lauda.
Luckily, a timely opportunity did present itself in that the French element of the F3 team were in contact with the French Prost F1 team, raving about Button's ability.