Yogeshwar, the 2012 Olympics bronze medallist in the 60kg category, was on the backfoot right from the initial stages and lost on technical points at the Carioca Arena 2 on Mat B.
Two-time World Wrestling Championships bronze medallist Mandakhnaran's aggressive intent was too much for Yogeshwar, who was nearly pushed out of the wrestling zone early on.
The Indian was able to avert that danger, but the 33-year-old Haryana grappler was soon cautioned while trying to grab his opponent's legs.
Yogeshwar's troubles grew further as he conceded a point for a successful tackle by Ganzorig, who led by the solitary point on Period 1.
Ganzorig upped the pressure in the next period and toppled Yogeshwar to lead 3-0.
It was always going to be difficult for the Indian to mount a comeback from there and with the clock ticking down, Ganzorig held on to win.
