Shapovalov seems to have all the tools a player needs to succeed, but give him time-a lot of time.
In other results, third-seed Dominic Thiem of Austria was upset 6-4, 6-7 (7), 7-5 by Argentina's Diego Schwartzman and Fifth-seeded Kei Nishikori of Japan, a finalist past year, was ousted 6-7 (4), 7-6 (7), 7-5 by Gael Monfils. You can't win every set, every match you play out there. He celebrated by falling onto his back then covering his face with his hands. "I'm going to try to make the most of it", Shapovalov said, as quoted by CBC Sports.
Federer, who was playing his first match since his emotional Wimbledon triumph, lost just three points on serve throughout what was an extremely one-sided contest.
The 27-year-old Nishikori had two chances to serve out the match and led 6-2 in the decisive tiebreak, before Monfils won six successive points to complete a superb fightback.
Elsewhere on Thursday, Roger Federer maintained his career-long winning streak over David Ferrer to advance to the last eight after a three-set battle with the veteran Spaniard.
"He's the best players I've ever played in my life". The big Argentinian was not at his best in the match, his famous forehand misfired more than it found the court. He let a set point slip away with Ferrer serving at 3-5, but Federer served out the second set in the 10th game. So was an important mistake for me. The Croatian took only 3 gems throughout the whole match, 6-1, 6-2.
Federer improved his head-to-head record against Ferrer to 17-0, but Ferrer took a set from Federer for the sixth time since they met for the first time in 2003.
Federer said that he did not get his rhythm until the end of the first set.
Some vintage play at the net helped put Federer 4-2 up with Ferrer seemingly unable to summon a response.
Blistering a 134 miles per hour ace down the middle for 4-all, Shapovalov blasted a forehand victor then earned match points when Nadal splattered a forehand into net.
Shapovalov is the lowest-ranked player - since the 144th-ranked Nick Kyrgios in the fourth round of the 2014 Wimbledon - to beat Nadal in a tournament.
The 19-time Grand Slam victor most recently extended his record against Spain's David Ferrer to 17-0 and will face another Spaniard in Roberto Bautista Agut on Friday in the Rogers Cup quarter-final. Last time that I played against him I lost, past year in Cincinnati.