Lisa Whiteside won her opening fight at the EU Championships in Hungary, beating Croatia's Hrvojka Cudina.
The England boxer from Preston forced Cudina to take a standing count in the first round, and a further two in the second before the 54kg fight was stopped on a technical knockout.
It was the police officer's first bout since joining the Olympic programme full time and taking a career break.
The 27-year-old won bronze in the Championships last time out in 2011.
Salford's 16-year-old flyweight Crystal Barker lost 3-0 to Turkey's Neriman Istik in the youth competition
Olympic goal medal winner Nicola Adams beat Italy's Terry Gordini on points to start her flyweight title defence on Monday.