Britains Cameron Norrie has been knocked out of the National Bank Open following a 2-6 6-7 (8) defeat against Arthur Fils in Montreal.The French 18th seed looked dominant early, utilising his powerful serve well to wrap up the first set without much hassle.Norrie stepped up a gear in the second, matching Fils power to force a tiebreak.Despite creating two set-point opportunities, Norrie was ultimately unable to convert when it mattered and Fils sealed the win in one hour and 43 minutes.Fils will face Spains Rafael Jodar in the quarter-finals, after he upset eighth-seed Jiri Lehecka in straight sets.Brandon Nakashima and Luciano Darderi also progressed to the next round with gruelling three-set victories over Arthur Rinderknech and Nuno Borges, respectively.Elsewhere, World No 1 Aryna Sabalenka was also knocked out in Montreal after losing to Russian Ekaterina Alexandrova 7-6 (3) 4-6 6-4 in the round of 16.Aryna Sabalenka also exited the competition in Montreal (Reuters)After winning the opening set, Alexandrova missed three break points as Sabalenka sent the match to a decider.The Belarusian went ahead in the third set, but Alexandrova rallied to take a 4-1 lead.Sabalenka managed to draw even, but double-faulted for her opponent to seal the win.Alexandrova will next face the winner of the face-off between Elina Svitolina and Amanda Anisimova in the quarter-finals.