Having won the 1988 British Formula Three championship he persevered with Onyx in 1989 and 1990 but the team collapsed halfway through his second season with them.
A move to Scuderia Italia saw Lehto take a stunning podium finish in the Dallara chassis at the rain-hit 1991 San Marino Grand Prix. But the following year he failed to score all season.
For 1993 he switched to Sauber and scored points early in the season but was largely eclipsed by Karl Wendlinger. Nonetheless he beat competition from Michele Alboreto and Luca Badoer to land a seat at Benetton alongside Michael Schumacher.
But his season was wrecked before it began. Lehto broke his neck in a testing accident, then having made a belated start to the season he lasted just four races before being pulled from the team. He returned to stand in for the suspended Schumacher for two races and rounded off the season back at Sauber – but that was the end of his grand prix career.
His subsequent career hinted at what might have been. He helped McLaren to a surprise maiden victory at the Le Mans 24 Hours, sharing an F1 GTR with Yannick Dalmas and Masanori Sekiya. He scored a second win ten years later for Audi with Marco Werner and Tom Kristensen.
A single season of Champ Car racing in 1998 was less successful, yielding a best finish of fifth for Hogan Racing at Surfers’ Paradise. In America too he fared better in endurance racing, winning the Sebring 12 Hours twice.
In June 2010 he was involved in a speedboat crash which claimed the life of the person he was sharing the boat with. After initially receiving a prison sentence Lehto successfully had the charges overturned on appeal in November 2012.