With his father 'Pop' a noted Formula 3 racer in his own right, it was no surprise when Stuart followed in his footsteps, and from 1951 he was one of the formula's leading exponents. He spent five seasons in this cut-and-thrust environment before Connaught gave him a chance to race at the end of 1956.
Encouraging early-season performances in the Connaught, including victory in the Richmond Trophy at Goodwood and fourth place in the Monaco Grand Prix, then took Stuart into the Vanwall team for the rest of 1957. Some of his drives were brilliant, for example at Naples, where he led Hawthorn, and Reims, where he finished third. In World Championship races he displayed a rare blend of speed and finesse, but had only a fifth at Pescara to show for his efforts.
Although a slight, frail figure, Lewis-Evans embarked on a daunting racing programme in 1958, competing successfully in Formula 2 for BRP and in sports cars for Aston Martin, in addition to driving for Vanwall in Grands Prix. He played a crucial part in gaining the constructors' championship for the team but, in what should have been a glorious finale to the year at the Ain-Diab circuit in Morocco, Lewis-Evans' Vanwall VW57 crashed in flames after its transmission had locked. The poor driver was extricated from the wreckage suffering from terrible burns and, despite being flown back to England for expert attention, he succumbed some six days later in East Grinstead Hospital.