Sam Querrey has ended Kei Nishikori's hopes of back-to-back tournament wins with a three-set victory in the second round of the Shanghai Masters.
Nishikori, who won last week's Japan Open, stormed to the opening set, but he was pegged back by Querrey, who prevailed 2-6 6-1 6-4.
Nishikori broke Querrey twice in the first set and only lost two points on his first serve as he raced into a one-set lead.
However, Querrey dominated the second set without losing a single point on his serve to take the match into a decider.
Querrey and Nishikori exchanged break of serves before Querrey struck for a second time to seal victory and progress to the third round, where he will play Tomas Berdych.
