Tomas Berdych has given himself a chance of reaching the semi-finals of the ATP World Tour Finals with a victory over Janko Tipsarevic this afternoon.
The Czech Republic player was taken the distance by Tipsarevic, before eventually wrapping up the victory in a tie-break.
Tipsarevic, who was competing following Andy Murray's injury withdrawal, started the encounter brightly and claimed the opening set 6-2 having broken his opponent on two occasions.
World number seven Berdych responded positively in the next set, running out a 6-3 winner.
Both players held their serves throughout the deciding set, which was taken to a tie-break.
Tipsarevic spurned a match point during the breaker and Berdych punished that failure to win 8-6.
Berdych, 26, will now take on David Ferrer in his final group match.