Angela Lee is still ONE Championship's unbeaten women's atomweight champion following a very close unanimous decision victory over Mei Yamaguchi on Friday at the Unstoppable Dreams event in Singapore.

Looking to finish the only opponent who took her the distance in a highly-anticipated rematch two years in the making, Angela was unable to do so as many might have felt Yamaguchi deserved the decision victory given her late flourishes that resulted in knockdowns in the fourth and fifth rounds.

However, the Hawaii resident had done enough in the earlier rounds with her pressuring and submission attempts to secure the win and take her record to 9-0.

"You know, I couldn't get the knockout because Mei is such a tough opponent and so incredibly skilled," Angela said afterward, referencing the Singapore crowd's lack of patience at times. "It is incredibly hard to come in here and do what we do and it's probably the toughest job in the world."

"But we wouldn't be here without you guys and your amazing support, so thank you Singapore," she said.

The 21-year-old also mentioned how the Singapore crowd was a tough one, especially given her brother Christian's failed attempt at beating Martin Nguyen for the ONE featherweight title earlier on in the night.

Christian, now 9-2, was looking to avenge his only loss to Nguyen (11-2) and in the process, win a world title so that him and Angela could also become the first sibling champions in MMA as had been heavily promoted in the build-up to the event.

However, the fight largely underwhelmed with Christian wanting nothing to do with Nguyen's striking as the fight saw very little action resulting not only in the crowd booing multiple times but also the referee giving both fighters a yellow card for inactivity.

From what action there was though, Nguyen had the upper hand for majority of it barring the first round, but would only win via split-decision much to the surprise of everyone in attendance.

Despite being the one going forward, the Sydney native apologized to the crowd in his post-fight interview.

"I take full responsibility for what happened," Nguyen said. "That wasn't like me. I'm so sorry Singapore for such a s--t performance. Next time, I promise I'm going to go for the finish."

Nguyen would also tell reporters after the event that he still plans on having a rematch with ONE bantamweight champion Bibiano Fernandes after their first meeting ended in a close split-decision loss for him.

Meanwhile, Thailand's Sam-A Gaiyanghadao became the organization's first ONE Super Series Muay Thai champion following a third round win over Sergio Wielzen after the referee deemed the latter unable to continue.

Full results of the event can be seen below:

Angela Lee defeated Mei Yamaguchi via unanimous decision

Sam-A Gaiyanghadao defeated Sergio Wielzen via TKO

Martin Nguyen defeated Christian Lee via split decision

Shinya Aoki defeated Rasul Yakhyaev via submission (triangle choke)

Yodsanklai IWE Fairtex defeated Chris Ngimbi via unanimous decision

Eduard Folayang defeated Kharun Atlangeriev via unanimous decision

Amir Khan defeated Sung Jong Lee via TKO

Singtongnoi Por Telakun defeated Joseph Lasiri via TKO

Chao Xie defeated Meas Meu via TKO

Xie Bin defeated Shi Had Huang via TKO

Sunoto Peringkat defeated Roel Rosauro via unanimous decision