Rafael Nadal upset by Denis Shapovalov at Montreal Masters

Rafael Nadal, Denis Shapovalov — Aug 10, 2017; Montreal, Quebec, Canada; Rafael Nadal of Spain falls during his match against Denis Shapovalov of Canada (not pictured) during the Rogers Cup tennis tournament at Uniprix Stadium. USA TODAY Sports / Eric Bolte

World No. 2 Rafael Nadal suffered an upset defeat to Canadian teenager Denis Shapovalov in his Round of 16 match at the Montreal Masters on Thursday. Nadal entered the Canadian Open, the last ATP Masters 1000 event before the US Open, as the No. 1 seed a month after his fourth-round loss at Wimbledon.

Nadal clinched the first set (6-3), before dropping the second set (6-4) and eventually losing a tie-breaker in the third set. The 18-year-old Shapovalov, one of the fastest rising stars in the #NextGenATP circuit, made a memorable debut during last year's Rogers Cup and has followed it up this year with victories over Juan Martin del Potro in the Round of 32 and a win over Nadal -- arguably the biggest victory of his young career.

"He played well. He has great potential. I wish him the best. He played with the right determination." @RafaelNadal on opponent @denis_shapo pic.twitter.com/M4iAjKfYlk
— Coupe Rogers (@CoupeRogers) August 11, 2017

Roger Federer, meanwhile, survived Spanish veteran David Ferrer in three sets in his Round of 16 match at Coupe Rogers. With the victory, Federer set up Friday's quarter-final showdown against Roberto Bautista Agut.

Roger Federer a big fan of Denis Shapovalov

Federer, a big endorser of #NextGenATP talent, came away impressed with Shapovalov after watching the Canadian teenager play in the Wimbledon juniors a few years back. “He came out, had these big shots, great sliding serve and a lot of different types of shots, and I like to see that. I’m a big fan of his, and I’m sure we’re going to see a lot of Denis in the future," Federer said of the future star.

Earlier in this year, Denis Shapovalov had set a goal of reaching the Top 150 of the Emirates ATP Rankings. But his success at the Canadian Open should catapult him into the Top-100 and he has set his sights on the inaugural Next Gen ATP Finals, which will feature the finest 21-and-under singles players on the Tour.

The 2017 US Open will get underway on Aug. 28. With Novak Djokvic and Andy Murray dealing with recurring injury woes, the tennis world is expecting either Federer or Nadal to continue their dominance of 2017 with another age-defying feat. The ongoing Montreal Masters is the last stop for the athletes before the final grand slam of the year at Flushing Meadows.