Mehta sealed the match with a couple of 40 breaks in the last frame.
On Saturday, Mehta had defeated Pakistan's national champion Muhammad Asif 4-2 and Mubarak Alowais of Kuwait 4-0 yesterday.
"It feels good to be winning consecutively for the third time opposite tough competitors. Personally, it is quite an achievement for me today considering that Karam currently holds the highest break of the tournament," said an elated Mehta.
The Indian still has three more matches to go. Only two of the seven players will qualify for the last sixteen after which it gets into a knockout format.
Mehta will now play against local favourite Bashar Hussain Abdulmajid tomorrow.
