 During the 1934 Tour, he was poised to be race leader after his team leader Antonin Magne crashed during stage 16.Vietto was unaware of Magne's situation; his advantage gave him the virtual race lead.A marshal on a motorcycle caught Vietto to inform him his captain was on the side of the road, with team-mate Lapébie ahead, and the other team-mates behind the yellow jersey.