كتب : Omar AbdelAziz
The Egypt midfielder netted the opener five minutes from the break, before UAE international striker Mohamed Sorour ensured the victory in injury time.
The Reds have 18 points on top of the standings, while Al-Shaab are second from bottom with four.
Ahli, who won their fourth game in a row, are facing fierce competition from Al-Ain and Al-Jazira, who registered wins at the weekend to remain in pursuit.
Al-Ain have 17 points in second place and Al-Jazira are third on 16.