Complex sentence: On October 21 2005, he became the sole recipient of all five first prizes at the 15th International Frederick Chopin Piano Competition in Warsaw, taking First Prize and the polonaise, mazurka, sonata, and concerto prizes.
Split into simpler sentences: On October 21 2005 he was the sole recipient of all five first prizes at the 15th International Frederick Chopin Piano Competition in Warsaw. Specifically, he took First Prize and also the polonaise, mazurka, sonata and concerto prizes.