Training under Vladimir Shelkovnikov, Voronina's major debut came at the 1966 World Championships in Dortmund, Germany. There she won a bronze medal on the floor exercise, receiving the highest individual score of any gymnast at those games (9.933), which might have been the first time that any woman gymnast broke the 9.900 score barrier in the post-1952 era, presaging the perfect 10s that Věra Čáslavská would score the next year at the 1967 European Championships and the perfect 10s that Nadia Comăneci would score so famously at the 1976 Montreal Summer Olympics.