Al Shabab took the lead at Prince Abdullah Al Faisal Stadium after 17 minutes when Abdulaziz bin Saran capitalised on a mistake by goalkeeper Mabrouk Zaid but Osama Al Harbi drew Al Ittihad level with a header early in the second-half.
And with extra-time looming, Moroccan striker Aboucherouane gathered a lay-off from Naif Hazazi before stroking the ball home to help his side avenge their 4-0 humiliation in the King’s Cup final.
With Al Hilal and Ettifaq eliminated earlier, Al Ittihad are the lone Saudi team remaining in the draw for the last eight.
The first ever AFC Champions League clash between Saudi teams began in cagey fashion before a catastrophic error by Zaid handed the visitors the lead.
Gathering in a back pass on the edge of his area, the Al Ittihad keeper was quickly closed down by Bin Saran and as he attempted to dribble past the Al Shabab striker, Bin Saran nipped in and tucked the ball into the empty net just before it ran out of play.
Normally a central defender, Al Harbi was pushed up front as Al Ittihad tried to take advantage of his height and he headed over in the 33rd minute.
As the half came to a close, Renato’s overhead flick flew just wide and Hazazi climbed above two defenders to meet a Saleh Al Saqri cross but failed to direct his header on target.
But just 30 seconds after the restart Al Ittihad skipper Mohammed Noor kept the ball in play on the right touchline and shook off the attention of two defenders before whipping in a cross that was headed in at the near post by Al Harbi.
The hosts should have taken the lead in the 50th minute when an unmarked Hazazi rushed his shot which flashed across the face of goal.
With 13 minutes remaining, Noor’s through ball released Hazazi, who was denied by a brilliant save by Waleed Abdullah before Al Saqri dragged the rebound wide.
The game appeared destined for extra time but in the third minute of stoppage-time, Noor found Hazizi who held off the challenge of a defender before laying the ball off for Aboucheroune, who broke into the box before sliding the ball past Abdullah with a neat left-footed finish.