Andy Murray overcame a shaky start to power into the semi-finals of the Shanghai Masters with a 4-6 6-2 6-3 victory over Radek Stepanek.
The US Open champion, who has an outside chance of finishing the year as world number one, will face either Roger Federer or Marin Cilic for a place in the final.
He was forced to overcome some worrying moments against Stepanek before hitting top gear to remain on course for a third successive Shanghai Masters title.
Murray was in trouble in the fifth game, conceding three break points and finding the net on the third, and never recovered as the confident Stepanek took the opening set with ease.
Their fortunes reversed in a hard-fought second set with Murray looking more comfortable and capitalising on a double fault to break in the sixth.
A stunning forehand winner - executed at full reach having dashed the width of the court - in the third game of the deciding set helped Stepanek secure a crucial break.
But Murray broke back immediately in impressive style and barely broke sweat as he cruised to victory, Stepanek buckling beneath the pressure in the closing stages.