The favourites made an excellent start thanks to a goal from former Orlando Pirates striker Blaise Lelo-Mbele and a quick-fire double from Blaise Kouassi – his eighth and ninth goals in the competition – to make it 3-0 inside 18 minutes.
But the Sudanese have kept the tie alive with second half goals from Brazilian Paulino and Faisal Agab – a penalty – before Lelo-Mbele scored his second of the game.
El- Merreikh know that a victory by two clear goals in the second leg in Tunisia on November 24 will give them an aggregate victory on away goals, but that is easier said than done in Sfaxien’s own back yard.