Denmark’s rising tennis star Clara Tauson has revealed she was told her grandfather had died after her upset win over world No.3 Iga Swiatek in Montreal.

Tauson, ranked 19th in the world, reached the quarter-finals of the Canadian Open with a 7-6 (7-1) 6-3 triumph over Swiatek on Sunday local time (Monday AEST) to set up a clash with Australian Open champion Madison Keys.

Her strong run of form continued with a stunning 6-1 6-4 victory on Tuesday local time (Wednesday AEST), after which Tauson shared what she had been through in the time between matches.

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“I’m still in shock,” Tauson said in her on-court interview.

“Two days ago my grandfather unfortunately passed away. I really wanted to win for him today.”

The emotions spilled over and Tauson paused to wipe away tears, the crowd rallying around the 22-year-old with a loud ovation.

“I really wanted to come out here and show my best tennis for him, and hopefully he’s watching,” she said.

“He used to coach me a little bit playing tennis and drove me to almost every single practice from my school.

“It was tough news yesterday morning when I woke up, but I think it’s for the better. He was not feeling great for a while.”

Tauson will play through the grief again in a semi-final on Wednesday (Thursday AEST) against Naomi Osaka, who defeated 10th seed Elina Svitolina 6-2 6-2.

Tauson won two WTA titles in 2021 but had to wait until January this year to claim her third, winning the Auckland Open.

While trophies have been few and far between Tauson has risen from world No.50 at the start of the year to an expected career-high 15th after Montreal — and higher if she wins her semi-final and potential final.

Ninth seed Elena Rybakina and Canadian teen sensation Victoria Mkobo will face off in the other semi-final on Wednesday (Thursday).

On the men’s side, Australian star Alex de Minaur will face American fourth seed Ben Shelton for a spot in the semis.