Complex sentence: The fourth and last time that he won in Latvia allowed him to compete in the European competition in 1938 in Tallin, Estonia, against the great Czechoslovak wrestler, Nics.
Split into simpler sentences: The fourth and last time that he won in Latvia allowed him to compete once again in the European Competitions which took place in 1938 and were held in Tallin, Estonia. He went against the great Czechoslovak wrestler, Nics.