He replaced the hapless Michael Andretti later on in the year and stunned the F1 world by outqualifying Senna in his first race back. He scored his first podium finish in Japan.
More top-three finishes followed over the next three years but a race win still eluded him.
It was not until ace designer Adrian Newey joined the team at the end of 1997 that the Finn really caught fire.
The wins started to flow freely and he clinched his first championship in 1998 after a tense battle with Michael Schumacher.
He was less impressive the following year but still defended his title successfully, thanks mainly to Schumacher breaking his leg in an
accident at Silverstone.
Despite the odd wobble - he broke down in tears after spinning out of the Italian Grand Prix - he saw off the challenge of Eddie Irvine with a flawless drive at Suzuka.