Montreal:Novak Djokovic beat Mikhail Youzhny 6-3, 6-4 on Thursday to advance to the quarterfinals of the Rogers Cup.
The fourth-seeded Djokovic won the tournament two years ago, when it was last held in Montreal.
Djokovic will face either fifth-seeded Andy Roddick or No. 10 seed Fernando Verdasco.
Later matches included Andy Murray facing Juan Carlos Ferrero and Rafael Nadal against Philipp Petzschner.
Nadal's comeback from a 10-week layoff with tendinitis is both knees was cut short on Wednesday night when his opponent David Ferrer retired at 4-3 in the first set with a sore knee.
In an evening match, top-seeded Roger Federer plays Stanislas Wawrinka.