Eddie Alvarez and Demetrious Johnson will make their highly anticipated ONE Championship debuts on March 31 inside the Ryogoku Kokugikan in Tokyo.

The promotion made the announcement to the Associated Press on Wednesday afternoon.

Johnson (27-3-1), the former UFC flyweight champion and pound-for-pound best, will square off against Yuya Wakamatsu in a flyweight contest. The man known as “Mighty Mouse” was previously traded from the UFC for former ONE welterweight champion Ben Askren in a historic move earlier this year.

In terms of competition, Johnson was last seen dropping his 125-pound title to current UFC champion Henry Cejudo in their rematch at UFC 227 in August. This setback snapped his UFC record of 11 straight title defenses, which dated back to Sept. 2012.

Wakamatsu (10-3) most recently dropped a decision to Danny Kingad in September.

Alvarez (29-6, 1 NC), a former UFC and Bellator lightweight champion, will make his debut against Timofey Nastyukhin. The Philadelphia native previously ended his free agency by signing with ONE in October.

In his most recent contest, Alvarez suffered a TKO loss to Dustin Poirier in their rematch at UFC on FOX 30 in July. Prior to this, the self-proclaimed “Most Violent Fighter” earned victories over former champions Anthony Pettis, Gilbert Melendez, Justin Gaethje and Rafael dos Anjos, the latter of which earned his UFC championship.

He would however drop his belt to Conor McGregor in their highly-promoted fight at UFC 205 in Nov. 2016.

Nastyukhin (12-4) is also looking to right the ship after being finished at the hands of Saygid Guseyn Arslanaliev in September.

Both bouts are expected to be part of the previously announced flyweight and lightweight Grand Prix tournaments.

Also on the card, ONE atomweight champion Angela Lee will square off against ONE strawweight champion Xiong Jing Nan. Eduard Folayang will defend his lightweight title against Shinya Aoki, and Aung La N Sang will defend his middleweight title against Ken Hasegawa.