"It's a battle, it's for my dignity," said Imane Khelif, one of two boxers at the centre of the storm, after she outclassed Hungary's Anna Luca Hamori to win on a unanimous points decision and reach the semi-finals of the women's 66kg category.
The duo embraced at the end and shook hands, before the judges' verdict was delivered, and an animated Khelif left the ring in tears.
The 25-year-old is ensured of a medal because losing semi-finalists in the boxing take home bronze.
Taiwan's Lin Yu-ting, the other boxer facing intense scrutiny, can also guarantee herself at least a bronze on Sunday when she faces Bulgaria's Svetlana Staneva in the quarter-finals of the women's 57kg.
Khelif and Lin, 28, were disqualified from last year's world championships, run by the International Boxing Association (IBA), after failing gender eligibility tests.
The IBA said this week that the two boxers "did not undergo a testosterone examination but were subject to a separate and recognised test, whereby the specifics remain confidential".
Neither boxer is known to identify as transgender.
The row ignited on Thursday after Khelif took 46 seconds in her opening bout in Paris to dismantle the Italian Angela Carini, who was left hurt and tearful.
The IBA, which has no involvement in the Games after years of mismanagement, immediately criticised the IOC.
'Honour to Algeria'
Hamori, who had said before the fight that it was unfair to face Khelif, was booed into the North Paris Arena.
Khelif won comfortably after consistently driving the Hungarian back and scoring with repeated jabs to the face.
Hamori was magnanimous in defeat.
"I think it was a good fight," she said. "I wish good luck to my opponent and to the others in the semi-finals."
Algeria's president, Abdelmadjid Tebboune, was quick to congratulate Khelif, who like Taiwan's Lin boxed at the Tokyo Olympics three years ago but did not win a medal.
"You bring honour to Algeria, Algerian women and Algerian boxing. We'll stand next to you whatever your results in the next two rounds," he wrote on social media.
Khelif's coach Mohammed Chaoua said his fighter "deserves a medal for courage".
She faces Janjaem Suwannapheng of Thailand in the last four on Tuesday for a place in the final.
The IOC has leapt to the defence of Khelif and Lin, with president Thomas Bach on Saturday saying they were born and raised as women, and have passports saying that.
Ahead of Saturday's bout, Khelif's father Omar told AFP from their Algerian village: "My child is a girl.
"She was raised as a girl. She is a strong girl -- I raised her to work and be brave."
