The second leg of the semi-final is scheduled for mid-October and a draw will suffice for the Blood and Gold, who suffered a humiliating 6-1 aggregate thrashing from TP Mazembe of Congo DR in the last season's final.
Wide midfielder Youssef Msakni scored the only goal at a sweltering Hilal Stadium in Omdurman just four minutes after the kick-off to end his seven-match goal drought in the competition. It was the fourth goal scored by the 20-year-old in the Champions League this season, but his first since last April when he contributed one in a 5-0 demolition of Senegalese visitors Diaraf Dakar.
Hilal are generally much stronger at home than away in Africa and now face the bitter prospect of exiting at the semi-final stage for the third time in five years.
Wydad Casablanca of Morocco built a 1-0 home lead over Enyimba of Nigeria in the other semi-final on Saturday with Benin midfielder Pascal Angan nodding in a free-kick one minute before the final whistle blew.
The final will be staged during the first half of November with Wydad or Enyimba hosting the first leg in pursuit of a place at the FIFA Club World Cup in Japan.