Nigeria's national U-23 team suffered a 1-0 defeat to Sudan in the first leg of the 2019 Africa U23 Cup of Nations qualifiers at the Al-Merreikh Stadium on Thursday.
Walaa Eldin scored in the first half to help the home side to a slim win ahead of next week's return fixture in Asaba.
The Dream Eagles started the better of the two sides with Mainz forward Taiwo Awoniyi and Genk attacker Stephen Odey coming closest to firing them ahead.
Nigeria were however made to rue those misses on the stroke of half-time when Eldin Musa slotted past goalkeeper Adamu Abubakar.
The Olympic Eagles made three changes as they searched for an equalizer in the second half but were denied by Sudanese who defended doggedly.
Nigeria risk missing out on the 2019 U23 Afcon tournament which holds later this year in Egypt except they turn things around in the return leg in Asaba next Tuesday.