The 27-year-old lifted a total of 201 kg after the two rounds, 29kg more than Marie Hanitra Roilya Ranaivosoa (172kg), who finished second. Meanwhile, Hannah Kaminski (171kg) of Canada took the bronze.
In a remarkable performance, Chanu smashed the Commonwealth Games record in snatch. She obliterated the Games record in clean and jerk as well, and in doing so also set a new total lift record.
Mirabai Chanu started her campaign in the 49kg snatch category with a humungous 84kg lift in her first attempt. The Indian weightlifter looked in relative ease compared to the rest of her competitors.
She then went on to create a new Games record and Commonwealth record in her second attempt with an 88kg lift. However, the 27-year-old still had to wait for another day as she failed to cross the 90kg mark in her third attempt.
At the end of the first round, Mirabai was way ahead of the others with a massive 12kg lead over second-placed Marie Hanitra Roilya Ranaivosoa (76kg) of Mauritius and Loa Dika Toua (74kg) from Papua New Guinea, who finished third.
Mirabai then lifted a whopping 109kg to set a new Games record in the clean and jerk round. Despite a gold medal assured, the Indian weightlifter did not stop as she then went on to lift 113kg in her second attempt to improve the record she had set in her previous attempt.
The Manipuri tried to lift 115kg in her third and final attempt but failed to convert, nevertheless, handed India its maiden gold medal at the 2022 Commonwealth Games.
Mirabai successfully defended her Commonwealth Games gold medal as she had earlier won gold for India in the 48kg weightlifting at the 2018 edition of the quadrennial event in Gold Coast.
"I am happy with my performance. I had said earlier I was competing with myself here. Everyone knows Commonwealth Games is easy for me but I never take it lightly. There is pressure of having it easy as well. I know what areas to improve on going forward," she said with a beaming smile after the medal ceremony.
Chanu had matched her personal best in snatch, considered not the strongest part of her game, and she was pleased about that.
"I felt my technique in snatch is getting better. I came back from Tokyo Olympics knowing I needed to work on snatch and that would benefit me going forward. I still need to do more with my technique to touch 90kg," she said.
Her next big target will be the World Championships in December.
Asked how she would celebrate, Chanu said that would happen once she reaches India. For the night, she will finally get to gorge on a pizza without the fear of gaining weight.
"My target at World Championships is to match my record in clean and jerk (119kg)." On the one sided nature of the contest and other lifters going for much lower weights, she said: "I look at what they are doing but my focus is on the six lifts I need to do."
(With inputs from PTI)