Al Jazira's Arabian Gulf League title challenge suffered a major blow as a 1-0 derby defeat to Al Wahda ensured Al Ain's lead was stretched to seven points.
Jazira had been looking to keep the gap at four points after Al Ain's 2-1 victory over Al Nasr, but Eric Gerets's side fell short to give the pacesetter another boost with just four matches left.
The match's only goal arrived in the 17th minute, as Santiago Tagliabue proved to be the difference, moving Al Wahda to within two points of the AFC Champions League spots.
Third-placed Al Shabab was made to battle for a 2-2 draw at home to Al Wasl, coming from behind twice and eventually securing a point with Edgar Silva's 75th-minute penalty.
At the other end of the table, Al Sharjah secured its top-flight status thanks to a convincing 4-1 defeat of Ajman, which itself appears doomed for the drop as it remains 10 points adrift of safety with four games left.
Already-relegated Al Ittihad Kalba claimed only its third win of the season in a 1-0 triumph over Al Dhafra, while Bani Yas drew 1-1 at home to Al Fujairah and Al Ahli beat Emirates 1-0.