Dienst is one of only four men to have twice refereed a European Cup final, which he did in 1961 and 1965, and one of only two (the other being the Italian Sergio Gonella) to have refereed both the European Championship and the World Cup finals. He refereed the original 1968 European Championship final, which ended in a 1–1 draw between Italy and Yugoslavia. The final was replayed two days later; refereed by the Spaniard José María Ortiz de Mendíbil, the Italians won 2–0.