Tokyo: World champion and world No. 1 Kento Momota defended his men's singles title with a straight-sets win, while Akane Yamaguchi beat Nozomi Okuhara in an all-Japanese women's singles decider at the Japan Open on Sunday.
In front of the cheering home crowd, top seed Momota won a tight first game against Jonatan Christie of Indonesia 21-16 before cruising 21-13 in the second.
It is the first time that Japan has won both the men's and women's singles titles at the Japan Open, an HSBC World Tour Super 750 tournament held since 1982.
"I didn't get good results last week and I wasn't confident of a repeat," said Momota, who made a second-round exit from last week's Indonesia Open in Jakarta as the top seed and defending champion.
"But so many people were rooting for me, and thanks to all of you I was able to win. I hope to keep working hard knowing that I have that support," he said.
Momota reached No. 1 in the Badminton World Federation men's singles world rankings last September and has held the top spot since then. Though he was disqualified from taking part in the Rio Olympics, he is leading the race to win Olympic gold in 2020.
In April 2016, Momota and his teammate were slapped with an indefinite ban by the national badminton association for illegal gambling, but he made a winning return at the Japan Ranking Circuit competition after a year's absence.
Earlier on Sunday, world No. 2 Yamaguchi beat third-ranked Okuhara 2-0. The much-awaited contest between the country's top two female shuttlers, however, lasted just 46 minutes.
In a repeat of their 2015 Japan Open final, Yamaguchi won a total of 42 points compared to 28 for Okuhara, and reeled off seven consecutive points at one stage to build up a comfortable lead and eventually close out the first game 21-13.
In the second game, where Okuhara showed signs of a return to form, Yamaguchi turned a 10-8 deficit into an 11-10 lead and pulled away to win 21-15.
"It's the first time I've ever won two weeks in a row and there's a feeling of accomplishment," the 22-year-old Yamaguchi said.
"I had a bad feeling when we started out with long rallies. But it was good I was able to regain control of the moment and play with perseverance," she said.
It was Yamaguchi's first Japan Open title in six years, and follows last week's championship at the Indonesia Open.
In the women's doubles final, the Japanese pair of Wakana Nagahara and Mayu Matsumoto missed out on their first title, going down 2-0 to South Korea's Kim So Yeong and Kong Hee Yong.
The July 23-28 Japan Open held at Musashino Forest Sport Plaza, which will host the Olympic badminton competition next year, is a test event for the Tokyo Olympics.