Andy Lee and Mamadou Thiam both weighed in above the middleweight weight limit ahead of their bout in Limerick on Saturday night.
Lee tipped the scales at 162.25lbs, while Thiam came in at 160.5lbs. However, the fight will go ahead as scheduled.
Speaking immediately afterwards, local hero Lee revealed that he is not underestimating the threat posed by his French rival.
"This is a must-win fight for me. I can't afford any slip ups and I will have to be wary of Thiam's power," he said.
"He's a dangerous guy and has an awful lot of experience and but these are the kind of fights I need to be winning if I'm going to go on to fight for European and World titles."
Thiam, however, believes that he can pull off a shock win.
"I'm not here for a holiday, I'm here on business. It's nothing personal between me and Andy Lee but I am very confident that I can win. I am punching harder than ever and I can knock guys out with either hand so I won't need to rely on the judges."