Al Ahly surrendered their Group D lead after losing 1-0 to AS Vita away in Kinshasa on Saturday.
A late strike by teenage forward Tuisila Kisinda was all that Vita needed to sink the record eight-time champions at the Stade des Martyrs.
The result saw the Egyptian giants losing for a second straight game to slide down from the group summit to second place, a point below leaders JS Saoura.
With the three points, Vita handed themselves a lifeline by rising from the bottom of the group to third position, tied on seven points with Al Ahly.
Playing goalless for the better part of the match and with little goalmouth action, 19-year-old Kisinda had the final say six minutes from time after connecting an assist by Ducapel Moloko.
Al Ahly had to witness goalkeeper Mohamed El-Shennawy being taken off the pitch in the 25th minute with an injury and had to be replaced by Aly Lotfy.
However, Lotfy was not troubled in goal until Kisinda hit to decide the contest.
Meanwhile, there were some shake-ups in Group D after Saoura beat Simba 2-0 at home in another match to dislodge Al Ahly from top spot.
Veteran forward Ali Yahia Cherif and midfielder Mohamed Hammia scored in either half to hand victory to Saoura who will now visit Al Ahly in their final group stage match next week.
It was also a night of revenge for Saoura who had suffered a 3-0 thumping at the hands of Simba in their opening match of the group in Dar-es-Salaam and have now notched up a four-match unbeaten run.
Cherif fired the Algerians ahead 18 minutes into the match, before Hammia stepped up to convert from the penalty spot six minutes after the interval.
With Simba dropping from second place to the basement of the group, all teams in this pool switched positions, creating an interesting scenario in which they will enter the final group round all with a chance of reaching the last eight.
Elsewhere in Abidjan, Asec Mimosas boosted their chances of progressing to the quarter-finals with a crucial 2-0 win over visiting Wydad Casablanca.
Ahmed Toure grabbed a second-half brace that saw Asec vacate the foot of Group A and into third place.
Although they failed to enter the top-two, Asec are still in with a chance as they now prepare for a trip to Lobi Stars next weekend.
The Ivorian giants are now tied on seven points with second-placed Wydad who had beaten them 5-2 in the reverse fixture in Casablanca.
On Saturday, they had to thank Toure, who broke the deadlock following a goalless first half by finishing off Gbagnon Badie’s assist on 68 minutes.
Wydad’s hopes of a comeback then went up in smoke with just a minute to go when Toure delivered the killer blow by completing his double after being set up by Salif Bagate.