Roger Federer battled to a brilliant three-set win over Juan Martin Del Potro to set up a semi-final clash with Rafael Nadal at the World Tour Finals.
The Swiss, 32, won 4-6 7-6 (7-2) 7-5 and will face world number one Nadal in the last four at 1400 GMT on Sunday.
Federer trailed in all three sets and came back from 3-0 down in the decider against fourth seed Del Potro.
Novak Djokovic, who plays Richard Gasquet at 2000 GMT, faces Stanislas Wawrinka in Sunday’s second semi-final.
Source: BBC Sport.
