Momoko Ohtani will face three-time French Open winner Yui Kamiji in the first all-Japanese women's wheelchair singles final at Roland Garros after the relative newcomer pulled off an upset victory over the defending champion on Thursday.

Tournament debutant Ohtani stunned the No. 1 seeded Dutchwoman Diede de Groot 7-5, 6-4 to reach her first Grand Slam final while No. 2 seed Kamiji beat reigning Wimbledon champion Aniek van Koot of the Netherlands 6-2, 6-2 in the other semifinal.

"I didn't think a day two Japanese players meet in the final would come so soon and I'm happy," said the 25-year-old Ohtani, who booked her final spot shortly before Kamiji.

"I was relaxed and was able to focus on my game today," she said.

Ohtani, playing just her second Grand Slam event following her debut at last month's U.S. Open, started competing as a wheelchair tennis player in 2016.

Kamiji won the French Open in 2014, 2017 and 2018. Kamiji and Ohtani met in the quarterfinal of the U.S. Open, with Kamiji winning 6-2, 7-6 (7-5).

Elsewhere, Japan's Shingo Kunieda, who was knocked out by Belgium's Joachim Gerard in the men's wheelchair singles semifinal 7-5, 2-6, 6-4 on Thursday, managed to advance to the doubles final with his Argentine partner Gustavo Fernandez.