Second seed Roger Federer marched into the semi-finals of the Australian Open with a 7-5, 6-4, 5-7, 6-3 win over Argentina's David Nalbandian on Wednesday.
The Swiss, who has dropped just two sets in the tournament, overcame Nalbandian in just over two-and-a-half hours to set up a showdown with world number three Juan Carlos Ferrero on Friday.
Federer snatched the first set from eighth seed Nalbandian with a break in the 12th game.
In the second, the Wimbledon champion twice recovered from a break down to stretch his lead.
Nalbandian pulled a set back when he broke Federer in the 11th game of the third but the Swiss wrapped it up by winning the fourth set.