MONTREAL - Clara Tauson wore a heavy heart when she took the court Tuesday night.

Tauson delivered a composed performance to reach the National Bank Open semifinals, ousting No. 6 seed Madison Keys of the United States with a 6-1, 6-4 win in the women's singles quarterfinals.

Then the 22-year-old from Denmark dedicated the victory to her grandfather, Peter, revealing during an on-court interview that he had died on Sunday.

“I really wanted to win for him today,” she told the crowd at IGA Stadium, wiping tears from her eyes while fans applauded her courageous performance. “I really wanted to come out here and show my best tennis for him, and hopefully he’s watching.”

Tauson said she found out about her grandfather’s death Monday morning, a day after she eliminated world No. 3 Iga Swiatek in straight sets.

About an hour after Tuesday's match, she spoke of him as one of the biggest supporters of her career.

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

"I just pushed it aside until the match was done. And then obviously, when it's done, you can let the emotions go a little,” she added. “I tried the past 48 hours to just focus on the match, and now I got the win, and then I'm going to try to push it away again and be ready."

The 16th-seeded Tauson will face four-time Grand Slam champion Naomi Osaka of Japan, who cruised to a 6-2, 6-2 victory over No. 10 seed Elina Svitolina of Ukraine.

The heartbreak comes amid a stellar run for 16th-seeded Tauson.

With wins over Swiatek and Keys, this year’s Wimbledon and Australian Open champions, Tauson claimed multiple top-10 wins in a single event for the first time in her career. She also hasn’t lost a set at the WTA 1000 event.

Tauson hit five aces, converted three of six breakpoint opportunities while saving all three she faced, and won 59 per cent of the points against Keys.

Tuesday’s results continue a trend of upsets at the National Bank Open. The top eight seeds are now out of the 96-player tournament.

Canadian teenage sensation Victoria Mboko takes on ninth seed Elena Rybakina of Kazakhstan in the other semifinal Wednesday. Mboko, who’s playing in her first main draw at the National Bank Open, will rise into the WTA’s top 50 after beginning the year outside the top 300.

The 18-year-old from Toronto has defeated five higher-ranked opponents en route to the semifinals, including top seed and world No. 2 Coco Gauff in the fourth round.

Keys failed to convert two breakpoint chances in the first game. After the American held serve, Tauson won the ensuing five games to take the first set.

"Not my best performance out there today,” Keys said. “She played amazing tonight, she played incredibly well, she served really well. It was just one of those things where I felt like I kept trying different things, and she was just beating me.

"When she's serving like that, it's going to be really hard to break her."

Now the second Danish player to reach the Canadian Open semifinals in the Open Era after Caroline Wozniacki, Tauson still believes she can find another gear.

"Even the last two matches, I don't think I've reached my top level,” she said. “But I've been playing really consistently and serving well. I think if I play even better, it's going to be even harder for the opponents.”

Osaka, meanwhile, reached her first WTA 1000 semifinal since 2022. The former world No. 1 is enjoying a resurgence after missing the entire 2023 season while on maternity leave.

"I'm really happy. I'm also really excited,” Osaka said. “After Wimbledon (third-round loss), I was really disappointed, and then I just kind of let go of my expectations. And now we're here.

“I find it kind of ironic, but I'm happy about it.”

In the only previous meeting between the two semifinalists, Tauson won the ASB Classic final in Auckland when Osaka retired due to an abdominal injury after winning the first set 6-4.

Tournament organizers in Montreal moved the women’s doubles final to Wednesday afternoon after it was initially scheduled for Thursday following the singles final. American duo Gauff and McCartney Kessler will take on the third seeds Taylor Townsend of the United States and Zhang Shuai.

The National Bank Open ends Thursday, the same day the Cincinnati Open main draw begins. Mboko automatically qualified for the tournament’s main draw by reaching the semifinal in Montreal, but her team hasn’t decided whether she’ll make the quick turnaround to Ohio, coach Nathalie Tauziat said Tuesday.

This report by The Canadian Press was first published Aug. 5, 2025.