Before Agyarko’s win, Tyrone McKenna also triumphed in his home city as he stopped Dylan Moran for the second time.
In a repeat of their welterweight contest from last year, a superb attack from McKenna in the seventh dropped the Waterford man, and while he briefly returned to his feet, it was not long before the referee stopped the fight.
In the build-up, 35-year-old McKenna suggested that Saturday’s appearance at Windsor Park could be the final fight of his career, but he indicated a willingness to fight on in the immediate aftermath of his 25th win.
“It was a war. I wanted a war and he brought it more than I thought,” said McKenna.
“I felt fresh so I knew I could take my time. He wasn’t hurting me but I was hurting him. He didn’t have power and everything I threw was doing damage, so that was coming.
“I’m never, ever retiring, I love it.”
Earlier in the night, Pat Brown beat Austine Nnamdi in a cruiserweight contest, Matthew Boreland beat Ruadhan Farrell, Caine Singh overcame Donagh Keary and Aaron Bowen defeated Carlos Miguel Ronner.