Bitter rivals Booba and Kaaris ended up behind bars in August after a running battle between their entourages shut down part of a Paris airport.
Yet a month in solitary confinement, heavy fines and the threat of 18 more months behind bars has done nothing to cool their animosity.
Hostilities flared again between the rivals on Christmas Day, when traditionally goodwill is supposed to reign between all men.
After an exchange of angry greetings on social media, the pair said they would compete in a no-rules cage fight in the New Year.
Kaaris, 38, was the first to break the truce by challenging his rival to “come and get me. You know where to find me”.
Booba, known as the “Duke of Boulogne”, rose immediately to the bait, posting a video of himself on Instagram stripped to the waist to reveal his muscled and tattooed torso.
“I am waiting for the day, for the hour, brother. No referee, just an octagon,” he said, referring to the type of cage used in ultra-violent mixed martial arts.
“I'll eat your bones, I'll eat drink your blood.”
'No referee. No rules'
Booba — aka Elie Yaffa — laid down the ground rules for the rumble.
“I am ready to take it to a Thai or normal boxing contest over 10 rounds,” he wrote.
“I am sure it would be a cake walk to fill Bercy,” he added, referring to the Paris stadium which is often used for rock concerts.
Kaaris accepted the challenge, insisting on the MMA octagon “without referee or rules” and demanded they fight this weekend.
The exchange of insults set social media alight, with mocking memes comparing the grudge match to the big money boxing match between boxing legend Floyd Mayweather and Irish MMA star Conor McGregor in 2017, that the American won.
Airport bosses said the August brawl “endangered the lives of others” and lodged a public order complaint against the singers after the ruckus forced officials to temporarily shut down the departures hall.