The ATP Montreal Masters suffered another major blow Wednesday as its top two seeds exited the tournament within hours of each other, with Germany's Alexander Zverev stunned in the second round and Canadian Felix Auger-Aliassime forced to withdraw because of injury.
Top seed and world No. 3 Zverev, the reigning French Open champion and Wimbledon runner-up, was upset by Dutchman Tallon Griekspoor, who rallied for a 6-7 (3), 6-2, 6-4 victory in the second round.
"I didn't expect to play well," Zverev said. "I also didn't expect to play this bad, to be honest."
Montreal native Auger-Aliassime withdrew ahead of his scheduled night match after suffering a back injury during a training session Monday.
"It was quite sudden. I was training here for two weeks and I had zero problems," Auger-Aliassime said. "Just the timing is tough.
"I thought that day by day things would get better, but I tried to go on court today, I tried to warm up, and then I basically couldn't serve really, so it was impossible for me to think about even competing."
The latest setbacks added to the tournament's growing frustration after world No. 1 Jannik Sinner and Novak Djokovic were both ruled out before play began, leaving the event without several of its biggest stars.
"I'm not going to lie, we were hoping that Felix was going to win at least a few matches," tournament director Valerie Tetreault said.
"He's definitely the player everybody was talking about and people wanted to know when he was going to play."
Zverev was competing for the first time since his Wimbledon final loss to Sinner and began to fade in the second set against world No. 69 Griekspoor.
"This was probably the worst match of the season," Zverev said. "This one was up there as the worst.
"Tennis comes with ups and downs. I'm very happy with how the last couple of months were. Now it's about getting back to that form."
Griekspoor came within a point of taking a 5-2 lead in the third set but found himself level at 4-4 after being broken.
The Dutchman responded immediately, breaking Zverev's serve again before closing out one of the biggest victories of his career in the next game.
"This is one of the most special wins I've ever had," he said. "I've had a tough season. I was close to throwing in the towel a few times. But I've been working harder in practice and reaching a good level.
"I felt it was about time for a big win."
Fifth-seeded defending champion Ben Shelton rallied from 4-1 down in the second set to beat fellow American Jenson Brooksby 6-3, 7-5, winning six of the final seven games for his 28th victory of the season.
The son of former ATP player Bryan Shelton has won seven straight matches in Canada, needing 96 minutes to advance to the third round. He is 15-3 against fellow Americans since the start of 2025.
"Defending is tough. I had to get over pre-tournament nerves but I got my first straight-set win of the summer season," Shelton said.
"Jenson is a nightmare match-up for me. To win it is a huge positive."
Greece's Stefanos Tsitsipas fell 7-6 (3), 7-5 to 19-year-old Brazilian Joao Fonseca in the second round.
Fonseca, who fired nine aces and hit 31 winners, next faces ninth-seeded Casper Ruud, who avenged an earlier loss this season to Juan Manuel Cerundolo with a 6-1, 6-2 victory.
On a day when fans were issued heat warnings as temperatures reached 29 degrees Celsius (84 degrees Fahrenheit), Britain's Cameron Norrie beat Paraguay's Ignacio Buse 6-3, 6-3, while Washington Open champion Taylor Fritz lost 7-5, 6-3 to Argentina's Thiago Tirante.
