The classy McCormack won a unanimous verdict over Russia’s Khariton Agrba at welterweight for what he admitted was the biggest title of his career.
The 24-year-old will now be among the favourites to win gold at Tokyo 2020, where he intends to provide a glorious send-off from the amateur ranks.
McCormack said, “That was the best win of my career and now I’m going to push on and win the World Championships and the Olympics.
“I’m 100 per cent turning pro after the Olympics. I wasn’t physically or mentally ready after Rio, but now I’m dying to go pro after I’ve got that Olympic medal.”
McCormack has been the stand-out star of the tournament in the Belarusian capital, reaching the final in emphatic fashion after flooring Olympic silver medalist Lorenzo Sotomayor on Friday.
And he made no mistakes against the relatively experienced Russian, controlling the pace of the contest and landing the most notable punch with a jarring right uppercut midway through the second round.
But there was disappointment for British light-heavyweight Ben Whittaker, who felt aggrieved to drop a split decision verdict to Azerbaijan’s Alfonso Dominguez.
And Ireland featherweight Michaela Walsh was also in tears after dropping a tight split decision to experienced Bulgarian Stanimira Petrova. Walsh said, “I am absolutely heartbroken to get another silver but I feel I have announced myself at this weight and I am determined to go one better next year.”