Tommy Wright's reign as Northern Ireland Under-21 manager got off to a losing start as they were beaten 1-0 by Luxembourg in their opening Euro 2025 qualifier at Mourneview Park.
James Rodrigues' 13th-minute strike secured the visitors the points.
Wright's side managed only one shot on target despite dominating possession for long periods.
Luxembourg's winner came as Rodrigues lashed in a rebound after Selim Turping had struck a post with a fierce shot.
Callum Marshall hammered an effort into the side-netting as the hosts looked to respond before the break.
JJ McKiernan then had their best opportunity in the 54th minute after Carl Johnston took a long pass in his stride and picked him out in the box.
McKiernan met the ball with a good first-time shot on the slide but goalkeeper Eldin Latik stretched to tip around a post.
Jamie McDonnell got behind the defence for a late chance but put his shot wide.
The Northern Ireland Under-21s will hope to pick themselves up for their next outing against Ukraine in Poprad, Slovakia, on Tuesday.