Al Ahli dropped points for only the second time this season as they were held to a 2-2 draw by Al Jazira on Thursday.
The league leaders, who also drew their previous game, fell behind in the 32nd minute as defender Juma Abdulla put the visitors in front.
But the hosts looked to have secured all three points as a goal from striker Ciel and an injury-time strike from compatriot Grafite turned the game around.
Those their hopes were dashed in the third minute of stoppage time as another Ciel's Brazilian compatriot Ricardo Oliveira equalised to earn a share of the spoils for Al Jazira.
However, Al Ahli maintained their four-point lead over second-placed Al Shabab, who could only draw 1-1 at Al Wahda on Wednesday.
Attacker Adeilson put Al Shabab in front inside the first minute, but they could not hold as Argentine Damian Diaz levelled matters just before the hour mark for Al Wahda.
Al Nasr surged into the top three with a 6-1 win over Al Wasl, midfielder Habib Fardan scoring a double as the hosts cruised to an emphatic victory.
Bani Yas dropped out of the AFC Champions League spots due to a 1-1 draw with defending champions Al Ain.
Ghana international Asamoah Gyan proved to be the hero for Al Ain as he cancelled out Fawaz Awana's opener 11 minutes from time.
Elsewhere, Dubai moved out of the bottom two with a 2-1 win over Ajman, Al Dhafra won 2-1 at Al Shaab and Emirates played out a goalless draw with Al Sharjah.