Marin Cilic made his second Australian Open semi-final after world No.1 Rafael Nadal retired with a leg injury during a titanic struggle on Tuesday.
The world No.6 and former US Open champion won 3-6, 6-3, 6-7 (5/7), 6-2, 2-0 in 3hr 47min on Rod Laver Arena when Nadal pulled out in pain early in the fifth set.