(CNN) - Top seed and world number one Rafael Nadal of Spain has been knocked out of the Australian Open by compatriot and "friend" David Ferrer.
Hampered by a thigh strain from the beginning of Wednesday`s quarterfinal, the nine-time grand slam champion was visibly suffering as he went down 6-4 6-2 6-3 at Melbourne`s Rod Laver Arena to his Davis Cup teammate.
