Portugal Colonial - Zverev, Auger-Aliassime exit star-short Montreal Masters

Top seed and world number three Zverev, this year's French Open champion and Wimbledon runner-up, was toppled by Dutchman Tallon Griekspoor, who rallied for a 6-7 (3/7), 6-2, 6-4 second-round upset.

Montreal native Auger-Aliassime had to withdraw before his scheduled night match after injuring his back during training on Monday.

Tournament officials already were fuming at an event in which world number one Jannik Sinner and Novak Djokovic were both high-profile absentees even before the start.

"I'm not going to lie, we were hoping that Felix was going to win at least a few matches here in Montreal," 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 number 69 Griekspoor.

The Dutch winner came within a point of a 5-2 lead in the third set, but found himself square at 4-all as he lost serve.

But the underdog broke the seed straight back and served out the match in one of his biggest victories a game later.

"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 his second set to overhaul US compatriot Jenson Brooksby 6-3, 7-5, winning six of the last seven games for his 28th victory of the season.

- 'A huge positive' -

The son of a former ATP pro has won seven straight matches in Canada, taking 96 minutes to go through to the third round. He's 15-3 against countrymen 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."

After earning the first Montreal win of his career on Tuesday, Stefanos Tsitsipas was eliminated, the Greek former world number three falling 7-6 (7/3), 7-5 to Joao Fonseca in the second round.

The 19-year-old Brazilian winner was competing for the first time in a month after an early Wimbledon exit and fired nine aces among his 31 winners.

Tsitsipas broke Fonseca when he served for the match to reach 5-5, but a further break of the two-time Grand Slam finalist put Fonseca back in control, the South American firing an ace on match point a game later.

"I've played all of the top five," Fonseca said. "That has helped me use my mental strength."

Fonseca next pays ninth seed Casper Ruud, who avenged a loss earlier this season to Juan Manuel Cerundolo, advancing 6-1, 6-2 thanks in part to 16 forehand winners.

On a day when fans were issued heat warnings due to 29 Celsius temperatures, 11th seed Lorenzo Musetti, who missed two and a half months of play after a Rome injury last May, defeated Colombian qualifier Nicolas Mejia 7-6 (10/8), 6-2.

British number two Cameron Norrie beat Ignacio Buse of Paraguay 6-3, 6-3 while Washington winner Taylor Fritz fell 7-5, 6-3 to Argentine Thiago Tirante.

X.M.Francisco--PC