Teenager Stefanos Tsitsipas produced his third upset in as many days as he ousted defending champion Alexander Zverev in the Rogers Cup quarter-finals.

The 19-year-old – who had dismissed Wimbledon champion Novak Djokovic in the third round and Dominic Thiem in the second – pulled off a stunning comeback against the German, saving two match points to win 3-6 7-6 (11/7) 6-4.

Tsitsipas was down a set and a break halfway through the second set, but found inspiration on his forehand and rallied to 5-5.

A tense tiebreak followed, with the Greek player holding his nerve to save Zverev’s match points and force a decider on his fifth set point.

The pair exchanged breaks in the third, before Zverev sent a second serve long in the 10th game to hand Tsitsipas the match.

The teenager becomes the youngest player since Rafael Nadal in 2006 to conquer three top-10 opponents in one tournament.

He will now face another top-10 player – Kevin Anderson – in the semi-finals of the tournament in Toronto.

Anderson, the number four seed, won 81 per cent of points on his first serve and hit 12 aces as he thrashed Grigor Dimitrov 6-2 6-2.

The 32-year-old broke his opponent twice each set, but did not face a break point on his own serve throughout the match.

Meanwhile, world number one Rafael Nadal was forced to fight for his place in the final four, eventually beating Marin Cilic in three sets.

The Croatian dominated the 40-minute opening set, wasting no time in clinching a 6-2 lead.

But the Spaniard stepped up his level in the second, breaking twice to force a decider, and needing just a single break in the third to claim a 2-6 6-4 6-4 victory.

Next up for Nadal is Russia’s Karen Khachanov, who beat 2017 Montreal semi-finalist Robin Haase 6-3 6-1.

Khachanov served strongly against the Dutchman, losing just two first-serve points in his 55-minute win, and winning nine of the final 10 games.