The Belfast-born EU bantam champion earned a unanimous decision over the Italian No. 1 seed and current EU feather champion.
Walsh, who beat England’s Karriss Artingstal yesterday, will now meet Helina Bruyevich of Belarus in the quarter-finals with at least a bronze medal up for grabs.
Today’s win also qualifies Walsh for next year’s European Games in Belarus as the top ten boxers in her weight book tickets.
World Elite finalist Kellie Harrington and Grainne Walsh are in action in Sofia tomorrow.
Last 32
57kg Michaela Walsh (Ireland) beat Karriss Artingstal (England) 5-0
June 6
Last 16
57kg Michaela Walsh (Ireland) beat Alessia Mesiano (Italy) 5-0
June 7
Last 16
60kg Kellie Harrington (Ireland) v Katerina Humlova (Czech Republic)
June 8
57kg Michaela Walsh (Ireland) v Helina Bruyevich (Belarus)
Irish squad
57kg Michaela Walsh (Monkstown)
60kg Kellie Harrington (St Mary’s)
69kg Grainne Walsh (Sparticus)
Team Manager: Bernard Dunne
Head Coach: Zaur Antia
Coach: Dmitry Dmitruk