Courtney Duffus made his debut for Republic of Ireland Under-21s on Friday evening.
The powerful forward, 20, was named in the starting line-up alongside Harry Charsley for the Euro Under-21 qualifier against Slovenia.
It was the in-form midfielder Charsley who put Noel King's side ahead on 87 minutes before a 2-0 win was sealed in stoppage time.
The result leaves Ireland fourth in Group 2, with a win over Serbia on Tuesday offering the chance to go second.
In World Cup qualifying action, Bryan Oviedo was an unused substitute as Costa Rica defeated Haiti 1-0.