The Australian four-times champion stormed to victory in the sixth leg of the World Cup Driving season after a stunning performance from his team of horses: Bajnok 2, Carrington Park Ajax, Bill 22 and Lucky 294.
Exell flew through two tests, each time with a 10 second advantage over his rival, Dutchman Theo Timmerman, who had to settle for second.
Another Dutchman Koos de Ronde came in third.
It was the second successive year carriage driving has featured at Olympia - a sign of the class's growing popularity, despite not being an Olympic discipline.
Over two days in west London, the competition consisted of four horses, guided by a leader, assisted by grooms at the rear of the vehicle.
The goal for competitors is to pass through openings made out of cones topped with balls. If a ball is dropped or an opening is not crossed, there are time penalites.
In general, it is a test of manoeuvrability and speed. There are other variations - there may be a carriage with one or two horses, or many different trials, such as dressage or marathon - but London proved to be a test of manoeuvrability, to Exell's liking.