Federer survives London battle
Roger Federer and Novak Djokovic will do battle for the title at the ATP World Tour Finals.
Federer saved four match points in beating Stanislas Wawrinka in a tight semi-final last night.
Federer eventually defeated the Australian Open champion 4-6 7-5 7-6 in London.
Djokovic also needed three sets to outs Kei Nishikori in the other semi-final.
The Serb won 6-1 3-6 6-0.
Federer has beaten Djokovic 19 times in 36 meetings and has won this tournament on six occasions.
(File Photo: Gallo Images)
Twitter - @SportswaveAndre