Khalfan Ibrahim looked to have put Al Sadd on course to follow up last week’s 4-1 win in Doha after opening the scoring after seven minutes.
But after the home side improved as the first half progressed Brazilian striker Edinho equalised before half-time and Ali Samereh and Paulo Zaltron sealed the crucial three points in the second half.
With Mes needing to end of a run of two consecutive defeats, the home side suffered an early blow as Al Sadd opened the scoring after just seven minutes.
Midfielder Hasan Al Haydos looked to have wasted the chance to deliver a cross into the area but eventually found Ibrahim at the back of the Mes area and the striker showed superb control to bring down the high ball before curling it into the top corner over the stranded goalkeeper.
Mostafa Seyfi, though, should have equalised for the home side just a minute later but goalkeeper Mohamed Saqr produced a low diving save to turn away the header from the edge of the six yard area.
Mes’ Brazilian striker Edinho, who opened the scoring last week before Al Sadd ran riot in the second half, fired just over the crossbar for the home side after nine minutes.
But the visitors could have been two goals up after just 13 minutes but Mes were saved by the off-side flag after Tahir Zakariya slid home from close range.
Mes went on to dominate as the half progressed but struggled to create a clear-cut chance until Edinho, who had continued to pose the main threat for the home side, beat an unconvincing Saqr to a right wing corner to head home eight minutes before half-time.
Al Sadd were almost caught out in the first minute of the second half as Samereh raced clear but Saqr produced another good save to beat away the effort from the edge of the area.
But the resulting corner dropped in front of goal and deflected off an Al Sadd defender kindly into the path of Samereh, who fired home from inside the six yard area.
Gholamabbas Ashoubi had the home fans on their feet six minutes after the hour mark but his rising shot from the edge of the area only ruffled the net after coming back of the advertising board behind the goal.
But with seven minutes remaining Brazilian striker Zaltron picked the ball up on the edge of the Al Sadd area and after moving forward unchallenged poked the ball home with the outside of his foot.
Al Sadd were handed a chance to set up a tense finish after substitute Mohamaed Magid was bundled over just inside the area with six minutes remaining, but Leandro’s resulting penalty hit the crossbar.