Ghana-born new recruit John Antwi scored the only goal of the Group A penultimate clash to send the Egyptian giants temporarily to the summit of the group.
Whilst Ahly are within sight of a place at the last four courtesy the result, it is the opposite for two-time African champions, Esperance who crashed out of the second-tier continental club championship after four defeats at the group stage.
A point in the Bamako encounter by Etoile will hand them a place at the semis together with Ahly, making the ultimate matches in three weeks serve academic purposes.
After a bright start, Ahly stunned the home crowd with the opener after five minutes from a three-man move involving midfielder Abdallah El Said, starlet Ramadan Sobhi and Antwi. El Saied sent a through pass to Sobhi, and he squared the Ghanaian who slotted home past Esperance goalie, Moez Ben Cherifia, who had to pick the ball three times from the back of his net in the reverse fixture last June in Suez.
At other end, Ahly goalie Sherif Ekramy parried a Chaker Regui free-kick to safety before Fakhreddine Ben Youssef curling shot flew across the face of goal.
The second half was balanced with Antwi making way for fellow new recruit Malick Evouna of Gabon fame midway after sustaining an injury.
Ekramy ensured the three points remained in their kitty with a superb save from Haythem Jouini in stoppage time.
Fixtures
Group A
22.08.2015 19H00 Esperance (Tunisia) 0-1 Al Ahly (Egypt)
23.08.2015 15H30 Stade Malien (Mali) vs Etoile du Sahel (Tunisia)
Group B
22.08.2015 18H00 Orlando Pirates (South Africa) 2-0 AC Leopards (Congo