Shanghai: Japan's world number one Kento Momota roared back from a game down to defeat Shi Yuqi of China and retain his Badminton Asia Championships title on Sunday.
On a red-letter day for Japan in the Chinese city of Wuhan, Akane Yamaguchi became the first Japanese to win the women's crown with an emphatic victory over home player He Bingjiao.
In a repeat match of last year's World Championships final, second-ranked Shi powered into a 6-0 lead in the first game.
Momota - who beat Shi to win the world title - briefly drew level, before the 23-year-old Chinese took the opening game 21-12.
The 24-year-old Momota appeared to lack his explosive best and was behind early in the second game too, before forcing level at 11-11.
The Japanese top seed then belatedly found his rhythm and sealed the second game 21-18 with a delicious smash.
The momentum was all with Momota now and he clinched the title in 69 minutes by easily winning the third game 21-8 against a badly deflated Shi.
There was more joy for Japan at the home of their arch rivals as Yamaguchi, a silver medallist two years ago, romped to victory against fifth-seeded He 21-19, 21-9.
The 21-year-old Yamaguchi, the third seed, raced out of the blocks in both games against her stunned opponent from China, who is a year older.
Yamaguchi went 12-2 up in the first game and was ahead 11-1 in the second on the way to the title in just 42 one-sided minutes.
"Becoming the first Asian women's singles champion from Japan is not that important to me," said Yamaguchi with a hint of mischief.
"Instead, I was proud to be on the top of the podium surrounded by three Chinese opponents," she added, referring to He and bronze medallists Chen Yufei and Cai Yanyan.
Men and women badminton players now have their eyes on the Tokyo 2020 Olympics with the 12-month qualification period starting on Monday.