British qualifier Jack Draper stuns third seed Stefanos Tsitsipas in Montreal

World number 82 Draper fought back from a break down in the second set before he wrapped up a stunning 7-5 6-4 (4) success against the third seed

Jack Draper stunned Stefanos Tsitsipas in Montreal (Paul Chiasson/AP) (AP)

Jack Draper beat Stefanos Tsitsipas to claim his first victory over a top 10 player as he became the third Briton to qualify for the third round of the National Bank Open.

World number 82 Draper, who came through qualifying to reach the main draw, fought back from a break down in the second set before he wrapped up a stunning 7-5 6-4 (4) success against the third seed just before 1am in Montreal.

World number eight Tsitsipas was let down by his forehand and made 40 unforced errors throughout.

Draper, who will take on 17th seed Gael Monfils later on Thursday for a spot in the quarter-finals, was thrilled with his victory.

“This is why I put in all the hard work, for nights like this on stages like this,” the 20-year-old said in an on-court interview.

“Last week, me and my coach probably were thinking we weren’t even going to come here. We were going to maybe train a week, get a bit of confidence. But it paid off coming.

“He’s at the top of the game for a reason, someone I’ve looked up to the last few years. It’s just good to be out here and try to express myself on this stage.”

British number two Dan Evans shocked eighth-ranked Andrey Rublev to qualify for the tournament’s last 16 for the first time.

The 6-4 6-4 victory against the Russian was Evans’ fifth over a top-10 opponent, with the 32-year-old to next face 10th-seeded American Taylor Fritz.

Cameron Norrie will take on hometown hero Felix Auger-Aliassime for the second time in a week after the British number one defeated Botic van de Zandschulp in straight sets.

Norrie, who beat the Canadian on Saturday in the Abierto de Tenis Mifel semi-final for the first time in five meetings, moved through with a 6-1 6-2 win against the Dutchman.

Elsewhere, top seed Daniil Medvedev was beaten in three sets by Wimbledon finalist Nick Kyrgios.