Branca made his Formula One debut at the 1950 Swiss Grand Prix, finishing 11th, and briefly led the non-championship Formula One race in Circuit des Nations at Geneva in a Simca-Gordini. He scored a number of top-six placings in other minor races, his best finish being fourth at a Formula Two race at the Aix les Bains Circuit du Lac, before entering the and finishing in 10th place. Branca continued to race in 1951, retiring from the Formula One and finishing sixth in the non-championship Pescara Grand Prix, but finished competing in Grand Prix racing at the end of the year.