SHANGHAI    -   Three-set tussles have played a defining role in Andy Murray’s comeback on the ATP Tour, and he had to come through another to see off Juan Ignacio Londero in reaching the second round of the Shanghai Masters. Murray was impressive in making the quarterfinals of the China Open, where his run was ended by Dominic Thiem following a gruelling contest with compatriot Cameron Norrie in which the Scot appeared a spent force in the second set. The former world number one, a three-time winner in Shanghai, needed to work just as hard to see off Londero, who won the first set but could not complete what would have been a memorable victory as Murray prevailed 2-6 6-2 6-3 in an engrossing battle. As Murray continues to try to work his way back to the top of men’s tennis, a rising star in the sport, Denis Shapovalov, set up an enticing second-round clash with Novak Djokovic by beating Frances Tiafoe. Meanwhile, there was a surprise defeat for Marin Cilic, who was beaten in straight sets by Albert Ramos Vinolas. Three-time grand slam champion Murray was not shy of letting his frustration show as he was made to work extremely hard for his place in the second round by Londero.  Two players each expected to be future heavyweights met as Shapovalov faced Tiafoe, but it is the Canadian who is clearly further along in his development, and he provided evidence of that in a comfortable victory. The world number 36 eased to a 6-4 6-2 win over the American, who won only two points against his opponent’s first serve. Shapovalov’s win marked his first at the Masters 1000 tournament and means he will face world number one Djokovic for the third time this year. Djokovic beat Shapovalov in four sets en route to winning the Australian Open and also defeated the 20-year-old in straight sets in Rome.