After a long break from MMA to give birth to her daughter, the "Unstoppable" Angela Lee has returned stronger and more motivated to continue her supremacy.

As the main event of ONE: X on Saturday night, Lee had the home fans on their feet at Singapore Indoor Stadium as she retained her women's atomweight world title against No 1 challenger Stamp Fairtex of Thailand.

Withstanding fierce body shots from Muay Thai specialist Stamp in round one, Lee came out more aggressively in the second, closing in with boxing combinations before a rear-naked choke elicited a tap of surrender from her opponent with just 10 seconds left before the buzzer.

The convincing second-round submission win in Lee's first official bout since giving birth to her daughter in April last year, halted Stamp's incredible rise in her absence and prevented the former ONE Muay Thai and kickboxing world champion from becoming a three-sport queen.

Yet, Lee took the biggest pride in being a champion mom.

"This little girl right here is the reason you guys saw the best performance from me," Lee said during her post-fight interview as she held her daughter, Ava Marie, in her arms.

"I trained harder than ever and pushed myself more than ever. Because of her and because of my amazing team－United MMA and United BJJ－I transformed into this world champion you see today," added the 25-year-old, who is married to Brazilian fighter Bruno Pucci. "So, thank you, Ava Marie. Mama did it for you, baby girl."

Lee's previous fight was in October 2019, when she thwarted strawweight champion Xiong Jingnan's attempt to reign in two weight classes by choking the Chinese challenger to submission in Tokyo.

Lee was forced to take a break from fighting due to the COVID-19 pandemic and then due to her pregnancy, which she announced in October 2020. Since then, Stamp has shone with some pundits suggesting she could take Lee's throne.

"Angela is back from a long layoff. She's had the baby, so I'm not sure which Angela we'll see. It's a hard one to predict, to be honest. But the safe bet will be Angela. I guess I'll go with Angela," reigning men's middleweight and light heavyweight champion Reinier de Ridder said before the fight.

Rising star Danielle Kelly expected a tight contest too, but also marginally sided with Lee.

"I'm really impressed with Stamp. I mean, I feel like if they're going to keep this standing up, I feel like it's Stamp's world. But I've also seen Stamp, jiujitsu is her weakness. So, I believe if it gets to the ground, I feel like Angela Lee has the power," said Kelly, whose atomweight grappling bout against Japan's Mei Yamaguchi earlier on Saturday was declared a unanimous draw.

Lee improves to 11-2, but is undefeated at atomweight. Saturday's victory earned her a performance bonus of $50,000 from ONE Championship chairman and CEO Chatri Sityodtong.