Canadian teenager Denis Shapovalov shocked top seeded Rafael Nadal to reach the quarter-finals of the ATP Montreal Masters tournament. The Canadian's win spoiled the Spaniard's chances of returning to world number one. Nadal would have returned to No. 1 in the world, if he had defeated Shapovalov yesterday, and then Chung Hyeon or Adrian Mannarino today. The 18-year-old Shapovalov, who needed a wild card to get into the hard court tournament, beat Nadal in three sets 3-6 6-4 7-6. Meanwhile, Roger Federer maintained his career-long winning streak over David Ferrer to advance to the quarter-finals after a three-set battle with the veteran Spaniard. Federer won with scores of 4-6, 6-4, 6-2. Federer will play another Spaniard, Roberto Bautista Agut, in the quarter-finals. Bautista Agut defeated France'sGael Monfils in a gruelling slugfest, winning 4-6 7-6 7-6.