Janko Tipsarevic has claimed victory over Novak Djokovic after forcing through a final set at the ATP World Tour Finals in London.
The Wimbledon champion started the match on the front foot, claiming a 4-1 lead in just twenty minutes of the first set.
Despite crashing out to David Ferrer on Wednesday, the world number one found his form with some impressive ground strokes that couldn't be stopped by his fellow Serbian opponent.
While Tipsarevic, who entered the tournament after Andy Murray's departure, managed to hold his serve, Djokovic was too much for the 27-year-old and took the first set 6-3 convincingly.
The world number thirteen stepped up his game in the early stages of the second set and managed to hold serve despite pressure from the US Open champion.
Tipsarevic's efforts paid off with a break of serve over Djokovic in an attempt to draw level at the O2.
The 27-year-old continued to power his way through for the second set, and courtesy of a few mistakes from Djokovic, Tipsarevic forced a third and final set after claiming the second 6-3.
The US Open quarter-finalist went from strength to strength in the deciding set, breaking the serve of his fellow countryman for the advantage. Djokovic continued to falter and Tipsarevic took the match 6-3 in the final set.
Djokovic could still have a place in the World Tour semi-finals if David Ferrer defeats Tomas Berdych this evening.
