Mohamed Malalla Hassan got the home side off to a flyer, scoring inside the first minute as Emirates looked to further distance themselves from the relegation zone.
But the away side hit back almost immediately through Rashed Essa, with Ismail Ahmed putting Al Ain ahead after 21 minutes and Ibrahim Diaky adding the third early in the second period.
Essa doubled his tally 21 minutes from time and Mohamed Ahmed gave the score a resounding look at the death, as Al Ain continue their march towards a third Gulf League title.
Second-placed Al Jazira's 4-2 win at Al Nasr on Saturday ensured the gap at the top could not stretch to seven points, with the division's top scorer Mirko Vucinic scoring twice to take his tally to 21.
Al Shabab remain in the driving seat for the final AFC Champions League place with a 2-0 triumph at Al Sharjah, though Al Wahda remain just four points behind following a comfortable 3-0 victory at home to struggling Ajman.
Late goals were the talk of Saturday's two other clashes, as a pair of strikes in the last five minutes saw Al Fujairah come away from rock-bottom Al Ittihad Kalba with a 3-2 win, while Ederson's last-gasp equaliser salvaged Al Wasl a 2-2 draw at Bani Yas.
In the weekend's other clash, reigning champions Al Ahli defeated Al Dhafra 1-0.
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