A depleted Mohun Bagan, without skipper Baichung Bhutia, suffered a 0-4 drubbing at the hands of Al Karamah in their last AFC Cup Group D match and ended their season on a disappointing note, in Howrah, on Tuesday.
Bagan ended their AFC Cup campaign, losing all their six matches and conceding 19 goals.
The Syrian side, on the other hand, advanced to the pre-quarter-finals of the continent's second tier club competition.
Bagan's Brazilian striker Jose Barreto struggled to create chances as he missed his strike partner Baichung, who quit the club after being served a show cause for missing team training and an exhibition match at Jalpaiguri last week.