Rafael Nadal was on the receiving end of a stunning upset in the last 16 as second seed Roger Federer survived at the ATP Rogers Cup.
Top seed and 15-time grand slam champion Nadal lost in three sets to 18-year-old Canadian Denis Shapovalov in Montreal on Thursday.
Federer, though, scraped through to the quarter-finals after outlasting David Ferrer.
Meanwhile, German star Alexander Zverev moved into the last eight.
REMEMBER THE NAME
A star was born in Montreal on Thursday.
With Canadian icon Wayne Gretzky watching in the stands, Shapovalov rallied to stun Nadal 3-6 6-4 7-6 (7-4).
After becoming the youngest player to reach the last 16 at an ATP tournament since Nadal in 2004, Shapovalov continued his stellar run despite losing the opening set and falling 0-3 behind in the final-set tie-break.
It ended Nadal's hopes of returning to the top of the ATP rankings as Shapovalov prepares to face Adrian Mannarino, who saw off Chung Hyeon 6-3 6-3 to reach his first 1000 quarter-final.
-- Tennis TV (@TennisTV) August 11, 2017
FEDERER RECOVERS FROM SLOW START
The Swiss maestro did not have it easy against David Ferrer, but unlike Nadal, he managed to see it out.
Federer came back to prevail 4-6 6-4 6-2 over the Spaniard earlier on Thursday.
Losing the opening set snapped Federer's remarkable run of 32 consecutive sets won by the Wimbledon champion.
A last-eight meeting with Roberto Bautista-Agut awaits after he trumped Gael Monfils 4-6 7-6 (7-5) 7-6 (7-2).
IN-FORM ZVEREV SEES OFF AILING KYRGIOS
Zverev finally got the better of his Australian opponent on Thursday.
The talented German claimed a 6-4 6-3 win over Kyrgios, who was hampered by his troublesome hip throughout.
Zverev - who has now reached the quarter-finals or better at four ATP 1000 events this season - will take on Kevin Anderson for a semi-final berth.
Anderson dispatched Sam Querrey 6-4 6-1.
Grigor Dimitrov - the seventh seed - suffered a 7-6 (7-3) 4-6 6-1 defeat to Robin Haase, who saved eight of 10 break points.
Haase will meet Diego Schwartzman after the latter topped Jared Donaldson 0-6 7-5 7-5.