Williamson (6-0-KO4) beat Flatley (11-0-4) in the Senior ABA final when the pair were amateurs and despite his opponent appearing confident of revenge, Williamson is adamant nothing will prevent him announcing himself on the big stage come June 9.
Williamson said: “I’m delighted. I’ve been on some big shows already but I’ve been on quite early.
“This time it’s an eight-rounder against another unbeaten fighter so it’s my chance to shine.
“I think Jack’s a good solid fighter but he’s quite basic. I wouldn’t say he’s a proper all-round fighter. I should beat him convincingly if I want to get where I’m going.
“I don’t really feel nerves. I get a few butterflies but it’s all good news.
“They’ll be bright lights and I’m looking forward to fighting in front of a big crowd on what’s going to be a special night of boxing.
“I want to get to the very top so it’s just a case of doing the graft in preparation, taking care of this kid in emphatic fashion and moving on to bigger and better things.”
Williamson has trained relentlessly since turning professional but, far from coveting a holiday or period of relaxation, he maintains an uncompromising attitude to his work.
Williamson added: “I’m boxing in two weeks in my hometown. After I boxed in Belfast, I had two days off and then I was straight back in the gym. It’ll be the same between these next two fights.
“I’m not really a party person. I don’t go on the drink and I don’t hang about with people who drink. I just simply live boxing and that’s it.
“I keep working and I keep getting better. The better the opposition, the better I’ll be so I hope Jack brings his A-game to Manchester on June 9.”
Follow Troy Williamson on Twitter @TroyWilliamson_