Novak Djokovic kept up the pressure in the race for the year-end number one ranking with victory over Belgian David Goffin at the ATP World Tour Finals.
Djokovic had already qualified for the semi-finals, and completed the group stage with a 6-1 6-2 win.
The Serb, 29, needs to better Andy Murray's results in London to overtake the Briton in the rankings.
Murray won his first two group matches and plays Stan Wawrinka on Friday at 14:00 GMT.
More to follow.