Dutch cyclist Lex van Kreuningen began his career with a win at the 1959 edition of the Huijbergen one-day race, as well as several other podiums at amateur races in the Netherlands. Van Kreuningen also had success at the Tour of Bulgaria, winning two stages in 1959, followed by another stage win one year later. As part of the Dutch Olympic team he narrowly missed out on a medal at the Roma Games when he finished fourth in the 100 kilometres team time trial. During the early 1960s van Kreuningen won the Ronde van Limburg in 1960 and the Ronde van Nederland in 1963, along with stages at the Tour de l’Avenir in France in 1962 and 1963, before retiring in 1964.