Djokovic hits back to set up Fed clash
The world number one could not have been closer to the exit door and the end of his chances of holding all four grand slam titles at the same time but again he showed incredible mental resilience to save four match points and triumph 6-1 5-7 5-7 7-6 (8/6) 6-1.
Djokovic has made such recoveries his speciality, beating Federer from match points down at the US Open in 2010 and 2011 and coming through epic five-setters against Andy Murray and Rafael Nadal to win the Australian Open in January.