Ireland Under-21s will finish third in the European Championship qualification group after completing the campaign by winning in Luxembourg on Wednesday evening.
JJ Kayode marked his full debut at this level by heading Ireland ahead in Beggen after 35 minutes before sub Jamie Lennon extended the advantage on 65.
Kenan Avdusinovic pulled one back for the hosts with six minutes left but they lost captain Seid Korac to a stoppage-time red card to kill their comeback hopes.
With Ireland’s qualification hopes ended by Iceland in Sunday’s 2-1 defeat at Tallaght Stadium, Jim Crawford made six changes for the concluding fixture.
Players from various age-groups were capped during the campaign but the manager prioritised those featuring for the last time at underage level.
All but two of the starting side will have to earn senior caps to maintain their international career, with the likes of senior internationals Michael Obafemi and Lee O’Connor named among the subs.
Kayode and Mark McGuinness were the only two starters eligible for the next campaign and both made an impact on their full Under-21 debuts.
Kayode, on loan at Carlisle United from Rotherham United, led the line well when introduced against Icelanders and was again a handful operating at the sole striker.
But Luxembourg, who had scored in just one of their nine qualifiers, conjured a few early chances.
Striker Alessio Curci snatched a a fourth-minute effort which flew wide, while Timothe Rupil lost his footing from a free-kick awarded right on the 18-yard line.
Stout defending by the home side left Ireland utilising the flanks for their attacking raids.
Kayode got his head a cross from Zack Elbouzedi on 11 minutes which was easily saved by Jose Machado but a more pinpoint move 10 minutes before the break left the goalkeeper helpless.
Left-back Darragh Leahy had the time to telegraph his delivery into the box where Kayode rose perfectly to power his header beyond the stranded stopper.
Rupil, on the bench for the seniors in last night's scoreless draw against Azerbaijan, drew the first real save from Ed McGinty approaching the break but a fast start to the second half by the Irish gave them some breathing space.
Leahy smashed a rasping shot wide on 53 minutes before fellow League of Ireland representative Lennon finished at the back post, only to be adjudged offside.
McGuinness played his part in that set-piece and repeated it for the second goal.
His deft flick-on from Danny Mandroiu’s free-kick fell to Lennon who rifled a 12-yard shot on the turn beneath Machado.
Ireland were denied a third with 17 minutes left when Leahy’s shot was taken off the line by Leon Schmit and Avdusinovic made it a nervous finale by rocketing a 25-yard shot in off the underside of the crossbar.
Ireland were rarely troubled, though, and the dismissal of Korac proved to be Luxembourg's final act.
LUXEMBOURG: J Machado; L Bernardy, S Korac, E Dzogovic, L Schmit; K
, I Latic (L Duriatti 83), M Olesen; T Rupil, A Curci (L Coopmans 69), L Prudhomme (Y Schaus 69).
IRELAND: E McGinty; D McNamara, C Masterson, M McGuinness, D Leahy; T O’Connor (J Lennon 46), C Ronan; A Scully (D Grant 69), D
(W Ferry 76), Z Elbouzedi; J Kayode (M Obafemi 76).
Referee: Kaarlo Oskari Hamalainen (FIN)