Second seed Novak Djokovic fought back from a set down to beat Croat Marin Cilic and secure a place in the Paris Masters semi-finals.
The Serb won 4-6 6-2 6-3 in two hours and 12 minutes despite being a set and a break down.
Djokovic lost the opening set and went 2-1 down in the third before immediately breaking back and then moving ahead at 5-3.
He will face either Roger Federer or Kei Nishikori in the semi-finals.
Djokovic showed frustration on court, aiming an outburst at his box before serving for the second set, and breaking his racquet after dropping serve in the third.