The defender played the full ninety minutes of Ireland U21's vital 1-0 victory over Azerbaijan.
The game at Tallaght Stadium looked to be heading for a goalless draw, but a 96th-minute winner from Shaun Donnellan gave the hosts an important victory and sparked mass celebrations.
Sweeney almost got his name on the scoresheet, but it looks as if the defender's header came just after the ball had already crossed the line, which led to the goal being credited to Shaun Donnellan of Yeovil Town.
The win moves Noel King's side to within three points of group leaders Germany, with a game in hand, as they look to secure qualification to the UEFA 2019 U21 Championship.
Sweeney's appearance against Azerbaijan was the defender's second cap for his country during the international break, following his appearance against Iceland last week.