Giovani Henrique opened the scoring before Mohamed Ali Ben Romdhane was sent off near the end of the first half. Despite going down to ten men, Al Shamal equalised through a Riyad Mahrez penalty before the interval.
Al Sadd regained the lead after the break through Mohamed Camara, with Akram Afif and Roberto Firmino adding further goals. Al Shamal remained on nine points. Al Rayyan, on 17, are due to face Al Arabi on 31 October, leaving the lead provisional.