He began his career in show business at age sixteen, when Jorge Loguarro, a friend and coworker who moonlighted as a stage presenter, invited him to do likewise at the Salón Argentino on Corrientes Avenue.

[4] He appeared in numerous advertising spots in subsequent years, as well as in sportscasting, and would work with leading Argentine football announcer José María Muñoz during the 1966 FIFA World Cup.

Fontana also covered boxing, and was on hand for Nicolino Locche's 1968 Light Welterweight World Championship win, as well as for Ringo Bonavena's fifteenth-round knockout loss against Muhammad Ali in 1970.

[2] Fontana had a twelve-year relationship with tango vocalist Beba Bidart, and in 1970 married model Liliana Caldini, who was 20 years younger than him and with whom he had twin daughters.

[2] The sinking of the ARA General Belgrano on 2 May 1982, at the height of the Falklands War, prompted Fontana to organize a telethon for the benefit of the troops, 24 horas por Malvinas, hosted with Lidia Elsa Satragno on 7–8 May.

Following the Argentine defeat five weeks later, revelations surfaced that the donations, as well as the Islas Malvinas Patriotic Fund these were deposited into (totaling US$54 million), were largely misappropriated by the Galtieri regime.

The Radio Nacional studio was located across the street from Atahualpa Yupanqui's Buenos Aires address, and the noted folk singer-songwriter became a frequent, impromptu co-host.

[5] The avuncular host, winner of 14 Martín Fierro Awards (as well as one for lifetime achievement) and an Ondas Prize from Spain,[2] considered leaving the country where his name had been a household word.