Tallon Griekspoor stunned Canadian Open top seed Alexander Zverev with a brilliant comeback win in the second round on Wednesday.

Zverev edged a tight first set, but Griekspoor did not give the French Open champion another opening as he clinched a 6-7 (3-7) 6-2 6-4 win in just over two and a half hours.

Both players struggled to find an opening in the first set, though Zverev was forced to defend a set point on his serve to force the tie-break.

The German reeled off the first five points of the breaker, but it took him three set points to get over the line.

Griekspoor responded in some style though, winning the first four games of the second set, giving up just five points in the process.

The Dutchman comfortably forced the decider and looked set to take control of the third when he got another break in the fifth game on his way to a 4-2 lead.

Zverev broke back to level the score at 4-4, but then immediately failed to hold onto his serve and Griekspoor sealed the upset on his first match point.

Tallon Time

The Dutchman sends top seed Zverev packing, sealing another upset in Montreal! @OBNmontreal | #NBO26 | @Griekii pic.twitter.com/VcvBQn59BO

— ATP Tour (@atptour) August 5, 2026

There was another big surprise earlier on as Washington Open champion Taylor Fritz was beaten in straight sets by Thiago Agustin Tirante.

Fritz struggled physically throughout the second set, needing a medical timeout, with Tirante claiming a 7-5 6-3 victory.

Ben Shelton did book his place in the next round, though, taking just one hour and 37 minutes to beat his compatriot Jenson Brooksby 6-3 7-5.

Lorenzo Musetti will join him in the third round after a tough challenge from Nicolas Mejia. The Italian was pushed all the way in the first set before breezing to a 7-6 (10-8) 6-2 win.

Zverev falls at first hurdle

Zverev has now lost 50% (3/6) of his opening matches as the top seed at ATP Masters 1000 events – the highest rate of any player with multiple such main draw appearances since the format's introduction in 1990.

The fourth such win of his career overall, Griekspoor has defeated the top seed at an ATP-level event for the first time since his victory over Zverev in Indian Wells (round of 64) last season.

And it is another disappointing outing for Zverev, who was the top seed at an ATP Masters 1000 event for the first time since last year's Canadian Open – he has not won any of the last six ATP Masters 1000 events where he has been the top seed.

But Rafael Jodar did continue his fine recent form. He has put his defeat in the Washington Open final to Fritz quickly behind him with a comeback win in Montreal.

He beat Corentin Moutet 4-6 6-1 6-3 in two hours and 18 minutes, and now only two players have claimed more ATP-level match wins than him (21) since the start of this season's European clay swing – Zverev (29) and Jannik Sinner (25).