A solitary 76th minute strike from Al Shabab's Ghanaian goal-machine Godwin Attram on Wednesday was enough to hand Al Ain their first defeat in this year's AFC Champions League, as things get tight at the top of Group B.
The victory for Al Shabab, who were being coached by Abdullatif Al Husaini following the sacking of Ze Mario a few days earlier, put the Saudi Arabian champions level on points with Al Ain, just one point behind Group leaders Sepahan who are on eight.
Al Shabab started the game brightly and almost opened the scoring in the third minute but Abdoh Autef's powerful shot from the edge of the area slammed against the left post.
Twelve minutes later it was the turn of the right post to frustrate Al Shabab. Richard Manga collected a neat pass from Iraq international Nashat Akram, only to see his shot cannon off the upright.
The hosts were taking control of the game and Al Ain goalkeeper Waleed Salem did well to save Abdoh Autef's 22nd minute shot before Manga again came close 12 minutes later.
Al Ain seemed a shadow of the side that defeated Al Shabab two weeks earlier and weren't helped when they goalkeeper Waleed Salem went off injured to be replaced by Mutaz Abdulla on the hour mark.
Abdulla passed his first test in the 67th minute when he showed quick reactions to prevent Attram heading home Nashat Akram's cross.
However, the Ghanaian was not to denied and in the 76th minute he collected a pass from left back Abdullah Shuhail and rounded an Al Ain defender and keeper Mutaz Abdulla to score what transpired to be the only goal of the game.