World number one Novak Djokovic continued his fine form with a straight-set win over Canadian Denis Shapovalov in the Shanghai Masters.
Serbia's 16-time Grand Slam champion, who won the Japan Open last week without dropping a set, cruised to a 6-3 6-3 second-round victory.
Defending champion Djokovic, 32, will play American John Isner next.
Isner, 34, hit 19 aces and lost only six points on his first serve in a 7-5 6-3 win over France's Lucas Pouille.
Greek sixth seed Stefanos Tsitsipas, 21, edged out Canadian 19-year-old Felix-Auger Aliassime in a match between two of the most exciting talents on the men's tour.