New Zealander Caroline Powell, the 2010 Burghley winner, was third in the final Classics table, with Britain's Mary King fourth and 2010 Badminton champion, Swindon-based Australian Paul Tapner, fifth.
Klaasen, a 100-1 shot at the start of the tournament, had already beaten top seed Mervyn King on his way to the final and becomes the youngest ever world champion.