Stefanos Tsitsipas defeated his second seeded opponent in as many days at the Toronto Masters on Thursday, stunning Wimbledon champion Novak Djokovic 6-3, 6-7 (5/7), 6-3 to reach the quarter-finals.

The Greek teenager, who turns 20 on Sunday, followed up his defeat of seventh seed Dominic Thiem, beating four-time champion Djokovic, seeded ninth, in a first-time meeting.

But upsets were not in the plan of holder Alexander Zverev, who rolled over Russian Daniil Medvedev 6-3, 6-2 in just 52 minutes while never facing a break point. 

Tsitsipas, ranked 27, spent just over two hours in advancing to the first Masters 1000 quarter-final of his career. The 19-year-old forced the former world number one Djokovic onto the back foot in the first set but was unable to wrap up a straight-sets win as the 13-time Grand Slam champion claimed the tiebreak with the Greek firing long, having saved two set points.

In the third set, the teenager showed great composure to break for a 2-0 lead and then saved a break point for a 3-0 margin. He rounded off his afternoon with back-to-back winners to send Djokovic, the winner of 30 Masters titles, out on a first match point. It was just Djokovic's fourth loss in his last 25 matches while Tsitsipas goes on to face either second seed Alexander Zverev or Russia's Daniil Medvedev.

(With agency input)