Thompson entered a works Connaught for the 1952 RAC British Grand Prix with a Lea-Francis engine and qualified the car ninth on the grid. In the race he made up a position when Gordini driver Robert Manzon was forced to retire with a clutch problem. He managed to finish in fifth place, three laps behind race winner Alberto Ascari and ahead of 1950 World Drivers' Champion Giuseppe Farina, and behind teammate Dennis Poore.