(Photo credit: David Kirouac-Imagn Images)

Not even the greatest women's tennis aficionados could have predicted this final four at the National Bank Open in Montreal.

On Tuesday, unseeded Naomi Osaka of Japan and No. 16 Clara Tauson of Denmark punched their tickets to the semifinals of the WTA 1000 event. Osaka, a four-time Grand Slam champion knocked off No. 10 Ukrainian Elina Svitolina, 6-2, 6-2, while Tauson started brightly and held off No. 6 Madison Keys, 6-1, 6-4.

The two will meet in the second semifinal match on Wednesday. The earlier match will feature 18-year old Canadian upstart Victoria Mboko and the highest seed remaining, No. 9 Elena Rybakina of Kazakhstan.

Svitolina struggled with her serve in the first set, getting less than 43 percent of her first serves in and losing 9-of-12 second serve points. Osaka took advantage, converting 3-of-4 break point opportunities, while saving 4-of-5 of her own troubled service games.

In her best showing since in a WTA 100 event since reaching the finals at the Miami Open in 2022, Osaka won 16-of-18 points in efficient serving games and did not face a break point to advance. She will move up from No. 49 to at least No. 34, her highest ranking since returning to the tour 20 months ago.

Osaka credits new coach Tomasz Wiktorowski with her recent success.

'Honestly, I think for me what's working well is I am very confident in my fitness. I'm really comfortable just getting balls back now, and I really enjoy Tomasz,' said Osaka. But I enjoy his coaching style. He's very direct and to the point. For someone like me, who my thoughts scatter around often, it's very helpful,'

Tauson never trailed in her match vs. the 2025 Australian Open champion. She broke Keys' serve in the fourth and sixth games of the set and opened the second set with a break. Tauson, who defeated 2025 Wimbledon champion Iga Swiatek in the previous round, won a robust 72.9 percent of the points on her serve.

Tauson was playing with a heavy heart, revealing after the match that her grandfather had passed away on Sunday.

'I really wanted to win for him today,' said Tauson. 'I really wanted to come out here and show my best tennis for him, and hopefully he's watching.'

Osaka and Tauson did square off in the finals of the 2025 Auckland Open. Osaka won the first set, but had to retire, gifting the Dane her third career title.

--Field Level Media