Canadian teenager Denis Shapovalov produced a stunning upset, rallying to defeat top seed Rafael Nadal in three absorbing sets to reach the ATP Rogers Cup quarter-finals.

Nadal came up against 18-year-old Shapovalov, who became the youngest player to reach the last 16 at an ATP 1000 event since the Spaniard in 2004 after upstaging Juan Martin del Potro on Wednesday.

And hard-hitting Shapovalov continued his giant-killing run in Montreal after shocking the 15-time grand slam champion 3-6 6-4 7-6 (7-4) on Thursday.

Shapovalov lost the opening set and dug himself out of a 0-3 hole in the final-set tie-break to win through to the last eight after two hours, 45 minutes on court.

With Canadian icon Wayne Gretzky watching in the stands, Shapovalov did not look overawed from the outset, hitting an early nerve settler to hold serve in style in the second game.

The teenager took the match to Nadal with his aggression and power and he managed to fend off a break point in the fourth game, eventually holding for 2-2.

Nadal was relatively comfortable on serve as Shapovalov provided plenty of highlights on his racquet – the emerging talent hitting back-to-back jaw-dropping winners.

However, Nadal showed why he is regarded as one of the greatest of all time, dominating in the closing stages after breaking for a 5-3 lead before serving out the set to love.

Shapovalov did not bow down, though, earning his first break point of the match in the second game of the second set.

While he wasted his first chance, another opportunity came along and he took it for a stunning 2-0 advantage, just as Nadal threatened to run away with the match.

Shapovalov maintained the break and came within millimetres of extending that lead after twice being denied by Nadal in the sixth game.

And it came back to haunt him as Nadal broke back, silencing the home crowd, before levelling the match at 4-4.

That unrattled Shapovalov, but only momentarily after breaking Nadal fortuitously to force a third and deciding set.

There was nothing to separate the two players, especially in the third game as Shapovalov grinded out a 10-deuce hold of serve after more than 14 minutes.

Shapovalov continued to go toe-to-toe with Nadal until the decisive tie-break, where the Spaniard appeared set to book his spot in the next round, only for the former to come storming back.