FIFA has, in accordance with the ruling, ordered the Saudi club to pay about 4 million euros to the Moroccan player.
The management of Al Nasr had, last November, unilaterally terminated the contract of the Moroccan striker, claiming that it had legal reasons justifying its approach.
Following this termination, Hamdallah had referred to FIFA to claim the amount of the release clause stipulated in his contract.
Commenting on the verdict of the international soccer body, legal sources close to the case explained that the Saudi club should ask the reasons for the verdict within 10 days and then have 21 days to file an appeal, noting that the case will most likely end up before the Court of Arbitration for Sport (CAS).