The Olympian was the unanimous winner as she came up against Natalia Shadrina of Serbia at the 73rd Strandja Cup in Sofia.
Harrington won the first round on all five judges’ cards she got the nod from four of the ringside officials in round 2 which left her in an unassailable position barring a knock-out.
It is the first time the Dubliner has fought competitively since taking home gold at the Tokyo Olympics.
Meanwhile, Roscommon middleweight Aoife O’Rourke also defeated her Panamanian opponent, Atheyna Bylon, by unanimous decision in the middleweight final.
