Sudan defeated Nigeria 1-0 in the first leg of the 2019 Africa U23 Cup of Nations qualifiers at the Al-Merreikh Stadium.
Walaa Eldin Musa scored the only goal that separated both teams as Sudan held on to a crucial first-leg advantage.
Nigeria started the game on the stronger foot but failed to convert their chances with Mainz forward Taiwo Awoniyi and Genk attacker Stephen Odey coming closest to firing them ahead.
The West Africans paid for their missed opportunities when Eldin Musa placed his effort past goalkeeper Adamu Abubakar on the stroke of half-time.
Despite making three changes in the final 20 minutes of the encounter, Sudan fought off the challenge from the Olympic Eagles to bag a crucial first-leg victory in front of their home fans.
Nigeria face an uphill task to overturn the defeat in Asaba next Tuesday. They risk missing out on the 2019 U23 Afcon tournament later this year in Egypt.
In the competition, African nations will hope to secure a ticket for next year's Olympic Games in Tokyo.