Main event switched as Vitaly Bigdash forced out of with an injury.
The 33-year-old Yamaguchi is 14 years Lee’s senior and will bring an incredible amount of cage experience.
Angela Lee and Mei Yamaguchi will battle it out for the promotion’s first women's world championship title on 6 May.
You’ll be hard-pressed to find a fighter more dominant in ONE Championship today than Singapore’s Angela Lee.
All athletes to move up a weight division.
ONE bans weight cutting by dehydration, challenges UFC to follow suit.