He participated in sports car racing between 1949 and 1955 taking his greatest success by finishing third in the 1951 Les 24 Heures du Mans and took part in the 1952 RAC British Grand Prix.

He took part in his only Formula One race in the 1952 RAC British Grand Prix finishing fifth, and later spent more time working at Lloyd's.

[4] In 1949 Thompson made his debut in the Les 24 Heures du Mans with HRG sharing his drive with Jack Fairman.

He also took part in the 1950 24 Heures du Mans sharing an Aston Martin DB2 with John Gordon but was forced out after nine laps due to engine failure.

He later competed in an ERA/Delage and Delahaye and other Libre races, and took part in sports car events with an Aston Martin DB2 in the RAC Tourist Trophy where he finished third in his class and eighth overall.

[3] For the works team, Thompson shared a DB2 with Lance Macklin in the Les 24 Heures du Mans where the pair clinched victory in the 3-litre class and finished third overall.

[6] In 1952 Thompson took part in his third Les 24 Heures du Mans driving an Aston Martin DB3 alongside Parnell but retired from transmission problems.

[3] Throughout the year he drove a DB2 entered by Peter Walker, clinching two victories in handicap events at Goodwood and one at Snetterton with a seventh and eighth at the same circuit.

Thompson took second, seventh and tenth in races at Snetterton, third at Boreham and Castle Combe driving an ERA/Delage and fifth in a private ERA at the British Grand Prix Libre event.

[3] 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.

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.

[8] Thompson participated in the 1953 Les 24 Heures du Mans in an Aston Martin DB3S with Poore with the pairing retiring with ignition failure after 182 laps.