Sand opened the scoring from the penalty spot in the 42nd minute and though the hosts came under intense pressure from Sepahan in the second half, the Argentine striker made the win safe with his second in the 71st minute.
Al Ain also had goalkeeper Yousif Abdelrahman to thank for the result as the UAE under-20 international made numerous outstanding saves to keep the Iranians at bay.
Sepahan could still have scraped through, however, had Pakhtakor beaten Al Shabab in the group's other game but the Uzbeks slumped to a 2-1 defeat in Riyadh.
With Al Ain using the offside trap to good effect in the first half, Sepahan were hardly in action while for the hosts, Omar Abdul Rahman - another UAE under-20 star pressed into service as five of the team’s regulars were either injured or serving suspension - was in good form.
The young midfielder, along with skipper Ali Al Waheebi and Sand harassed the rival defence but it took until the 42nd minute and foul by Mohsen Bengar on Sand in the area to earn them their first goal.
Sand sent Mahdi Rahmati the wrong way from spot and the home supporters, who were outnumbered by the Iranian expats in the Sheikh Khalifa Stadium, went wild with joy.
Sepahan’s Senegalese striker Ibrahim Toure was through with a long ball but Abdelrahman charged out to thwart the lanky striker four minutes after restart.
Four minutes later Emad Mohammed worked his way into the box and squeezed the ball to substitute Mahdi Jafarpoursorkhi but Abdelrahman grabbed the ball from the latter’s feet.
On the hour Bengar’s cross went begging and even as Sepahan piled on the pressure, Mehdi Karimian also joined the list of culprits when he shot over from close range.
Abdelrahman then saved a free-kick by skipper Moharram Navidkia and from a sudden counter-attack Al Ain made it 2-0.
Substitute Abdul Aziz Fayez dribbled into the box and though his feeble attempt was saved by the Sepahan goalkeeper, Sand pounced on the rebound to fire home.
Jafarpoursorkhi barged into the box in the 77th minute but Abdelrahman was equal to the task after the left post came in the way of Emad Mohammed’s shot.
The Iraqi then beat Abdelrahman but the post was again in the way and it seemed that apart from their profligacy in front of goal, luck had also deserted the Iranians.