World number two Andy Murray of Britain was knocked out of the ATP World Tour Finals by Swiss Stan Wawrinka 7-6 (7-4), 6-4 and missed a semifinal place at the O2 Arena here.
Wawrinka, the reigning French Open champion, who defeated Murray on Friday, will play compatriot Roger Federer in Saturday's semifinals, Xinhua reported.
World number one Novak Djokovic of Serbia will fight against fifth seed Rafael Nadal of Spain for the other final berth.
Murray, who will lead Britain against hosts Belgium in the Davis Cup final next week, made a total of 30 unforced errors and lost after one hour and 53 minutes.
Nadal, who had already secured top sport in his group, fought back from one set down to beat fellow Spaniard David Ferrer 6-7 (2), 6-3, 6-4 in two hours 37 minutes.
"It is very important for me to be finishing the season like this, competing well against the best players," said Nadal.
"Novak is playing almost better than impossible. He is achieving almost everything that one player can dream. I have to play to the limit of my best to have a chance," he said.