The Matchroom chief has been forced to go to hospital after cutting his head on a vase.
Hearn had been watching on as ‘Sugar’ stopped Shvkatdzhon Rakhimov in an IBF title eliminator in Tajikistan on Friday.
A video shared to Matchroom CEO Frank Smith’s Instagram story showed the aftermath of the celebrations.
The promoter could be seen wiping blood from his head with a towel, whilst parts of the broken vase were left scattered on the floor.
Asked by Smith what had happened, Hearn answered: “So, when Sugar Nunez stopped him, I jumped up to celebrate. I headbutted that (points to vase).”
He later reposted the clip to his own page, adding: “Off to hospital to get stitched after cutting my head open in the celebrations! Well done @SugarNunez97 that was incredible!”
Nunez has now moved to 26-1 as a professional after his 11th round stoppage win.
Meanwhile, Hearn and Matchroom are preparing for their latest event in Oaxaca, Mexico later on Friday.
The card is headlined by Adrian Curiel’s first defence of his IBF light-flyweight belt against Sivenathi Nontshinga.
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Hearn had earlier announced the highly-anticipated rematch between Josh Taylor and Jack Catterall.
The rivals are set to meet in the ring once again in Leeds on April 27.
Former world champion Taylor controversially won their first bout via split decision in 2022 to retain his light-welterweight titles.