Angela Lee faltered in her bid to become the first two-division women's champion in mixed martial arts (MMA) organisation One Championship last night, after she was beaten by China's Xiong Jingnan, who retained her strawweight (up to 56.7kg) title in Japan.

Lee, One's atomweight (up to 52.2kg) champion, lost via a technical knockout (TKO) in the fifth and final round at the A New Era event at the Ryogoku Kokugikan indoor arena.

Now, she has to look over her own shoulder, too.

One chief executive officer Chatri Sityodtong told the media last night that Xiong is considering dropping a weight class to contest for the 22-year-old's title.

Last night's loss was Lee's first in her MMA career, having won all nine prior fights, while Xiong improved her record to 17 wins and one loss.

"I think there's going to be a rivalry (between Lee and Xiong) in the future for sure," said Chatri.

"Jingnan is so dominant as a world champion, Angela was so dominant until today, and it was a crazy, crazy war. If Jingnan wants to fight at atomweight, let's do it."

Yesterday was the first time Lee, who has a Singaporean father and fights under the Singapore flag even though she is not a citizen, stepped into the cage since May last year.

But the Hawaii-based fighter showed no signs of ring rust in the early rounds against 31-year-old Xiong, who had defended her belt twice since Lee's last fight.

Lee came close to forcing a submission from Xiong in the fourth round after locking in an armbar, but the Shandong native refused to tap out despite major torque on her right elbow.

The effort appeared to drain Lee, who looked exhausted in the championship round; a bodyshot by Xiong set her up for a flurry of shots which led to the referee calling the stoppage.

Lee did not turn up for the post-event press conference, which was mainly attended by winners on the night.

When asked why she refused to submit, Xiong simply replied with a grin: "Faith."

Hailing the Chinese as the deserving winner of an "epic, epic" fight, Chatri added: "That arm was going to go, and 99 per cent of athletes would have tapped, but Jingnan is an absolute monster.

"It was clear by the fifth round Angela had emptied her gas tank and was no longer there, and Jingnan capitalised."

Prior to Xiong's win, there was plenty of drama elsewhere.

Former Ultimate Fighting Championship (UFC) star Eddie Alvarez was stunned by Timofey Nastyukhin, losing via a first-round TKO in his first fight since his high-profile signing in October last year.

Demetrious Johnson, another former UFC champion, fared better on his One debut, beating Yuya Wakamatsu with a guillotine choke in the second round.

One bantamweight (up to 65.8kg) champion Kevin Belingon, meanwhile, lost his title bout with Bibiano Fernandes via disqualification for illegal elbows to the back of the head.

But the Brazilian refused to be awarded the belt after the match, gesturing he did not want to win the title via his Philippine opponent's disqualification, before swiftly leaving the cage.

Chatri later insisted Fernandes is the champion "on a technicality", but said a rematch would be scheduled.

In the main event, submission specialist Shinya Aoki won the lightweight (up to 77.1kg) title in front of his countrymen after choking former champion Eduard Folayang out with an arm triangle in the first round.