Japan's former badminton world champion Emiko Ueno, who won the crown in women's doubles 40 years ago, praised Nozomi Okuhara on Monday for winning their country's second world title overnight in Scotland.

Ueno, 59, said the 22-year-old Okuhara, who defeated Rio de Janeiro Olympic silver medalist Pusarla Sindhu of India 2-1 in the women's singles final Sunday in Glasgow, had "a strong will that was uninterrupted" during the match lasting 1 hour, 50 minutes.

"She fought admirably with her small frame," Ueno said of her compatriot, who at 157 cm tall, rallied persistently, making Sindhu, who is more than 20 cm taller than her, unable to keep up with the shuttlecock.

Sindhu was given warnings several times for bending down during the match to take quick rests while pretending to pick up trash from the floor.

Okuhara has suffered from a string of injuries in her career. She underwent surgeries in both knees after she was crowned Japan's youngest national champion at the age of 16 years and eight months.

Even after she recovered, she succumbed to a right shoulder injury after she lost to Sindhu in the semifinals of last year's Rio de Janeiro Olympics, where she finished with a bronze medal.

"It is not easy" to come back strong from an injury, said Ueno, who also had multiple surgeries after she retired from the frontlines of the sport. "It must've been difficult for her to overcome it and finish where she is now."

Ueno, who won the women's doubles title with Etsuko Toganoo, now 67, in the inaugural world championships in 1977, predicted that Japanese players will keep improving.

The country claimed its record four medals at the just-ended world meet — Okuhara's gold, one silver and two bronze medals.