As an 18-year-old, Rochard surprisingly won the 5000 m in the 1931 national dual meet between France and Britain, running 15:11.8.

[5] His best time that year was 15:01.6, which he ran in Paris on 25 October,[3] but in that race he was defeated by Poland's Janusz Kusociński, who went on to win Olympic gold at 10,000 metres.

[6] In 1932 Rochard broke 15 minutes for the first time, running 14:56.8;[3][7] he was selected for the Olympic Games in Los Angeles, where he qualified for the final but did not finish it.

[7] At the 1934 European Championships in Turin Rochard was up against Kusociński, Virtanen and Ilmari Salminen, but outkicked them all and won gold by a clear 4.4 second margin.

[7][8] His winning time, 14:36.8, was his personal best; he only missed out on the French record, set by Jean Bouin in his duel against Hannes Kolehmainen at the 1912 Summer Olympics, by one-tenth of a second.