Despite a huge deficit, Dahiya did not panic, showing tremendous mental strength and dramatically turned the bout in his favour.
After the end of the first period, Dahiya had a 2-1 lead but Sanayev came prepared and attacked the Indian's left leg, getting a good grip of that turned him thrice to log six points in a jiffy.
Suddenly Dahiya's lead was gone and he was staring at a defeat but his superior stamina and technical prowess was still at work. The remaining one minute was enough for him to turn the tide and he did it in style.
He got hold of Sanayev with a double leg attack and then gripped him tightly, Kazkahstan wrestler's back on the mat and finished the bout with a might 'pin'.
Even in his previous bouts Dahiya was dominant as the 23-year won both his previous contests on technical superiority en route the final.
Dahiya outclassed Colombia's Tigreros Urbano (13-2) in his opener and then outwitted Bulgaria's Georgi Valentinov Vangelov (14-4).
He is now only the fifth Indian wrestler to have won an Olympic medal after KD Jadhav, Sushil Kaumar, Yogeshwar Dutt and Sakshi Malik.
Jadhav had become India's first wrestler and also the first individual Olympic medallist when he won a bronze during the 1952 Helsinki Games.
After that, Sushil Kumar enhanced wrestling's profile by winning a bronze at the 2008 Beijing Games and bettered the colour of the medal by claiming a historic silver in 2012 at the London Games that made him India's only athlete with two individual Olympic medals.
The feat since then has now been matched by shuttler PV Sindhu.
In the same 2012 edition of the Games, Yogeshwar Dutt won a bronze.
Sakshi Malik became the first Indian woman wrestler to win an Olympic medal when she took a bronze in the 2016 Rio Games.
This could well be a watershed Games for Indian wrestling with both Vinesh Phogat and Bajrang Punia also in contention.