Tai Tzu-ying
In October, Yamaguchi won her second Super Series title at the Korea Open, beating Sung Ji-hyun, the fifth seed. She followed this with a win at the Denmark Open held at Odense, making her the fourth non-Chinese women's singles player to win two consecutive Super Series after Tai Tzu-ying, Ratchanok Intanon, and Tine Baun. On her way to victory, Yamaguchi defeated her teammate Nozomi Okuhara in the quarterfinals and two-time World Champion and Olympic gold medalist Carolina Marín in a close three-set match in the semifinals. In the women's singles final, she defeated the No. 2 seed, Tai Tzu-ying, winning the tournament. This was her first Super Series Premier title in her career.