Ayrton Senna was the quickest Formula One world champion in history, according to Jackie Stewart.
Senna has been feted on the anniversary of his death
Three-time champion Stewart said: "He was probably the fastest champion I ever saw. He was always stretching the elastic. My goodness was he quick."
Martin Brundle, a former rival of both Senna and Michael Schumacher, said: "Senna had a greater God-given skill, Schumacher applies it in a better way."
And F1 boss Bernie Ecclestone said: "Ayrton was something quite special."
This year's San Marino Grand Prix marks the 10th anniversary of Senna's death.
And Ecclestone said that had Senna not been killed on 1 May 1994, Michael Schumacher would not have broken all the F1 records he has.
"If he was still with us, Michael wouldn't have been a six-time world champion.
"Maybe he would have been a two or three-time champion and Ayrton a four-time."
Senna won three world titles and 41 Grands Prix in his 10-year career.
He still holds the all-time record for pole positions, having started from the front of the grid 65 times in 162 races.