Rafael Nadal surpassed a fierce challenge against one of the rising stars in the game German teenager Alexander Zverev in 4-6, 6-3, 6-7 , 6-3, 6-2 battle to reach the last 16 of the Australian Open on Saturday. The Champions of 2009 had to be at his best to come out on top after more than four hours of fierce rallies and shot-making which earned both players a huge ovation from the spectators at the Rod Laver Arena.