Price had been stretched to her limit last time out against Nouchka Fontijn, edging out her Dutch rival on a wafer-thin split decision, but there was no such drama in Sunday afternoon’s final.
The 27-year-old from Wales was able to use her superior lateral movement to confound Li, getting in and and out of range at will and controlling the tempo throughout to claim a unanimous points win.
This was Britain’s 22nd and final gold of the Tokyo Games, cementing fourth spot in the medal table, while their six Olympic gongs in boxing is their best haul in 101 years.
Price, who becomes the second British woman after Nicola Adams in 2012 and 2016 to top the podium in boxing, was giving away several inches in height but dictated proceedings from the off.
Staying on the balls of her feet, Price, a former world kickboxing champion who has more than 50 international caps for the Welsh football team, controlled the distance expertly.
Li, the 2018 world champion, had not lost a round in her two previous bouts but all five judges sided with Price after the first three minutes.
The one-way traffic continued in the second round and after four judges sided with Price, Li needed to do something special. It failed to materialise and four scores of 30-27 and one of 29-28 went in Price’s favour as she added Olympic gold to Commonwealth and world glory she achieved in 2018 and 2019 respectively.
Away from the ring, Jason Kenny became the most decorated British Olympian ever, winning his seventh gold medal with victory in the men's keirin final in Izu.
However, it was disappointment for his wife Laura who crashed in the women's omnium, finishing in sixth place.