The Cameroonian, who caused a storm on social media over his age, helped his side to a 3-1 victory over Fiorentina
The 17-year-old has caused a storm on social media in recent weeks after a website claimed the attacker's real age was 42, prompting Lazio to threaten legal action over the suggestions.
However, the rising Cameroon star put the recent rumours firmly behind him with a match-winning display to put the Biancocelesti firmly in control of the final ahead of the second leg on April 9.
Gondo handed the Viola the lead with an early goal before Minala struck twice in the second period and defender Josip Elez added a third from the penalty spot.
Lazio will now head to Florence full of confidence as they look to secure their first Coppa Italia Primavera since 1979.