Mumbai City FC faced its second defeat in three games following their 0-3 loss against Al-Shabad side in their opener.
Mumbai City had to witness a narrow 0-1 loss against Al Jazira in a Group B match of the AFC Champions League here.
At King Fahd International Stadium on Thursday, Mabkhout's 40th-minute goal became the difference between the two sides as Al Jazira collected three points.
Coach Marcel Keizer's men dominated the first half, registering 70 per cent ball possession by the break.
But they struggled to create real scoring chances, as Mumbai City sat deep, happy to concede play and look to hit on the counter.
The Islanders suffered an early blow as defender Amey Ranawade was stretched off to be replaced by Methab Singh just nine minutes into the game.