Al-Merreikh beat Sudanese rivals Al-Hilal 2-1 in Cairo (Photo: CAF s official Twitter account)
Elsamani Saadeldin gave Merreikh a third-minute lead but Mohamed Abdelrahman brought Al-Hilal level on 32 minutes.
However, Saadeldin struck again three minutes before the break to give Merreikh a precious victory after they held South Africa's Mamelodi Sundowns to a goalless draw in their opening group-stage game last weekend.
Merreikh are now joint leaders of Group A with four points, on level with Sundowns.
Reigning champions Ahly of Egypt will move level with both sides if they defeat Sundowns in Cairo on Saturday.
In Group B, the hopes of Algeria's ES Setif to reach the knockout stage were dealt a blow after they slumped to a 1-0 loss away to South Africa's AmaZulu.
Luvuyo Memela netted the winner in the 42nd minute as AmaZulu moved level on six points with leaders Raja of Morocco, who have a game in hand. Setif lie third on three points.
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