A 27th minute strike from Salmeen Khamis gave the hosts the lead before a shot from Ismail Al Hammadi bounced off goalkeeper Murmur Ikramov into his own net to make it 2-0 on 58th minute.
With Ahli missing the services of strikers Makhete Diop and Ahmed Khalil due to injuries, Gyan stepped up and latched onto a pass from teammate Saeed Abdullah, before lobbing his effort over onrushing goalkeeper Ikromov on 72nd minute, with Everton Ribeiro making it 4-0 five minutes later.
The goal is Gyan's fifth of the season and second in the competition, and the win has helped Ahli to avoid fierce rivals Al Ain in the knockout stage. They will lock horns with Al Ahli Saudi Arabia while Al Ain face Iranian giants Esteghlal.
Gyan claimed the UAE Pro League Top Scorer Award in 2012, 2013 and 2014, the AFC Champions League Top Scorer as well as the AFC Foreign Player of the Year in 2014 during his first UAE stint.