Khelif booked her place in the quarter-finals of the women's 66kg contest after Carini abandoned the fight in just the first round.
Having received a couple of heavy punches in the opening seconds, Carini gave up the fight and went to her knees in tears.
The Italian boxer frustratingly threw her helmet to the ground and refused to shake Khelif’s hand before screaming 'This is unjust.’
Last year, Khelif was disqualified from the World Championships for failing a gender eligibility test following a series of DNA tests after her sex was questioned.
However, with the International Boxing Association no longer recognised by the International Olympic Committee (IOC), the boxer was cleared to compete at this year’s Olympics.
Khelif, who was previously disqualified for failing a testosterone level test, stepped into the ring against Carini on Thursday and wasted no time in sealing the victory.
Meanwhile, speaking to the media after the fight, Carini said she had to give up to preserve her life.
"I wasn't able to finish the match, I felt a strong pain to my nose and I said [to myself] for the experience that I have and the maturity as a woman that I have, I said I hope my nation won't take it badly, I hope my dad won't take it badly - but I stopped, I said stop for myself," she told BBC Sport.
"It could have been the match of a lifetime, but I had to preserve my life as well in that moment. I didn't have fear, I don't fear the ring. I don't fear taking the blows. But this time there's an end for everything, and I put an end to this match, because I wasn't able to [continue]."
Khelif’s participation at the Olympics has caused widespread outrage among sports fans, many of whom have called on the IOC to take action to protect biological female boxers.