He raced for Bugatti, Nacional Pescara, Alfa Romeo, Maserati, Torino, and Villa Padierna in the Grand Prix of the 1920s and 1930s, the predecessors of Formula 1.
He was the son of Nicolás Zanelli, an Italian immigrant who made a fortune in the nitrate fields of Antofagasta, and Adela de Vescovi, a native of Tarapacá.
He began to establish contacts with the European aristocracy, something very difficult at that time, especially for a South AmericanTheir shared passion was motorsports, which was then exclusive to the wealthy.
Juan Zanelli appeared in European motor racing competitions driving a two-seater Fiat, which had less power compared to the fast Alfa Romeos or Bugattis.
Additionally, he acquired a Bugatti and collaborated with important figures in motorsport, such as the Vizcaya brothers and Raúl Pateras Pescara.
On June 2, 1929, Juan Zanelli would be crowned the winner of the 1929 Bugatti Grand Prix at Le Mans, securing his first victory.
The official 1930 season of the World Motor Racing Championship began in April of that year with the Monaco Grand Prix at the Monte Carlo circuit.
Zanelli debuted a new Bugatti Type 35B in the Grand Prix, but due to a mechanical failure, he was forced to retire while in 4th place, with only 8 laps remaining.
This competition consisted of 40 laps around a 4-kilometer circuit and brought together top automotive figures from Spain, Italy, France, and the rest of Europe.
Zanelli won in 1 hour, 34 minutes, and 43 seconds, ahead of Vasco Sameiro, Marcel Lehoux, Joaquín Palacio, and Tazio Nuvolari.
The Penya Rhin Grand Prix was one of the most prestigious races of that time, later won by drivers such as Luigi Fagioli, Tazio Nuvolari, Giuseppe Farina, and Alberto Ascari, among others.
The goal was to create a racing team and launch a sports version to compete in the European Hill Climb Championship.
Other notable drivers in this championship included Hans Stuck, Carlo Felice Trossi, Wolfgang von Trips, and Edgar Barth.
While the Gestapo managed to identify most of those involved, Zanelli lost his life in a confusing shootout between Germans and resistance fighters.
Juan Zanelli remained lost in Chilean anonymity for a long time until he was "rediscovered" in December 2007 thanks to the research conducted by the author of the book "Coche a la Vista", lawyer Rodrigo Velasco.
The book unveils the little-known story of Juan Zanelli, a result of five years of investigation that involved traveling to Europe and the places where the driver had his best performances.