Russi made his World Cup debut at age 19 in January 1968 at a giant slalom in Adelboden. After two races in 1968 and six in 1969, he joined the World Cup circuit full-time in December 1969. However, his racing career was set back at this time by his work as a stuntman in the movie "On Her Majesty’s Secret Service" which was filmed in Switzerland and during which he fractured a cervical vertebra. After a period of rehabilitation from this injury, he was able, for the first time in several months, to compete in the Downhill Race at Val d'Isère on December 14, 1969, in which he placed 14th. He gained World Cup Points by recording his first World Cup top ten finish (tenth in the Downhill on January 10 on the Lauberhorn piste in Wengen). He went on to achieve a fourth place in the Downhill at Garmisch-Partenkirchen on February 1, leading to him being selected for the Swiss team at the 1970 World Championships, where he won his first event, the downhill, ahead of Karl Cordin of Austria and Australian Malcolm Milne. It was a race with fresh snow, and he was the 15th racer on the start list - a good number for such conditions. He won despite suffering a hand fracture a week before in a practice race, contending with the pain during his winning run. Notably, he skied his winning run without ski wax as his coach Paul Berlinger scraped the wax off his skis directly before the start. Because the World Championships counted towards the World Cup at this time, his World Championship win was also his first World Cup race victory.