Switzerland's Stanislas Wawrinka is into his first Australian Open semifinals after his four-hour, five-set win over Djokovic.
The second-ranked Serb is turning to the former world No. 1 to lead his team in 2014.
Master of many surfaces, Spaniard is four Grand Slam titles behind Federer, one back of Pete Sampras.
Scotsman's victory sets off a United Kingdom celebration.
World's No. 1 player wins longest semifinal in tournament history.
With crowd solidly behind him, Scotsman advances to semifinal against Jerzy Janowicz.