كتب : Omar AbdelAziz
The African champions looked set for a comfortable victory after a goal in each half from Mohamed Barakat and Amado Flavio put them in front.
However, the hosts produced a late show to snatch a draw thanks to two headers from Oscar Ntwagae and Jose Torrealba in the last 10 minutes.
Barakat showed what a genius footballer he is following his long absence, when he opened the scoring with a clinical finish in the 28th minute after being set-up brilliantly by Mohamed Shawki.
Sundowns committed men forward in search for the equalizer, but they were punished on the counter attack when Ahmed Al-Sayed dashed forward until he fed Flavio for the second goal.
The Angolan international striker made no mistake to double Ahli's lead ten minutes after the interval with a fine placed shot which goalkeeper Calvin Marlin should have done better to parry it.
Comforted by his 2-0 lead, coach Manuel Jose made several substitutions as he brought in Hossam Ashour, Osama Hosni and Hassan Mostafa to replace Barakat, Emad Meteb and Anis Boujelbene.
This maneuver hardly affected the game as the defending champions lost their pace.
The home side controlled possession in midfield with some slick passing but they were desperate to find the finishing touch until they pulled one back in the 79th minute.
A pinpoint cross from Surprise Moriri found defender Ntwagae and the latter placed a fine header to the left of Essam Al-Hadari as Ahli's defiant defense looked unusually exposed.
Sundowns sustained their assault and when Tarek Al-Saied lost possession cheaply in his own half, Josta Dladla capitalized to feed Venezuela forward Torrealba for the crucial equalizer one minute from time.
The draw makes Ahli in a more comfortable position to reach the quarter-finals phase when the time comes for the second leg scheduled for the 20th of April in Cairo.