Goals from Ismail Al Hammadi, Grafite, Adnan Al Baloushi and Majed Hassan gave the Dubai side the advantage in the race for second place.
Al Ahli up to second in Pro League with 4-1 rout of Baniyas
Ismail Al Hammadi gave Ahli an early lead and Grafite, the Brazilian forward, doubled it on the stroke of half time.
Adnan Al Baloushi added a third shortly after the break and Majed Hassan sealed the victory 20 minutes from time.
Nawaf Mubarak pulled one back from a swerving free kick but it was too late and too little for Baniyas.
Egyptian playmaker Mohamed Aboutrika could have reduced the gap but his effort from six yards out sailed over the crossbar four minutes from time.
It was an excellent result for the Dubai club, coming so soon after the Football Association's Disciplinary Committee awarded Al Ain a 3-0 victory against them for last week's abandoned match.
The game was headed for a 0-0 draw when the referee called the game off with three minutes of added time left when his assistant was hit by a mobile phone battery thrown by an Ahli supporter and required treatment on the pitch.
Ahli were in total control of the game against Baniyas until the last quarter. It was a remarkable performance from Quique Sanchez Flores's men against a team that had held on to the second spot in the standings for a long time.
They were creative in attack and solid in defence, keeping Andre Senghor, Aboutrika and Christian Wilhamsson on a leash throughout the 90 minutes.
The opening goal was all down to the creativity of Al Baloushi. He picked up a long ball, cut inside the box, drew out the goalkeeper Mohsin Al Hashmi, and chipped in a lofted pass for Al Hammadi to head it into the back of the net from eight yards.
Amir Mubarak could have doubled the lead had he been on target after man-of-the-match Luis Jimenez created space for him.
The Emirati midfielder Mubarak made up for it though with a superb through pass to Grafite, who timed his run to perfection to guide the ball past Al Hashmi for a 2-0 lead on the stroke of half time.
Al Baloushi had a simple tap in to the net from a low pass from Grafite to make 3-0 nine minutes in to the second half and killed off any hopes of a Baniyas comeback.
The margin of victory could have been more had Jimenez's effort not crashed against the post.
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