Joshi, number two in the rankings, shot a superb five-under 65 and had five birdies against no bogeys. Two of his birdies came on the last three holes.
Two shots behind Joshi was Syed Saqib Ahmed, also from Bangalore. He shot 67, while Simarjeet Singh (68) was lying third.
Three other players, Zubin Nijhawan, Sher Mohd and Udayan Mane carded 69 each.
Six others including Gagan Verma and Shubhankar Sharma shot even par 70 each to be tied seventh on a humid day which witnessed slight breeze.