Trailing Yan Han narrowly overnight after Friday's short program, Jin showed he meant business from the start with two immaculate quad jumps.
And despite then doubling what should have been a quad toe loop, the 22-year-old continued to delight the home fans in Chongqing with an exciting routine boasting artistry and spectacular jumping.
While his sixth place at Skate America all but ended his hopes of reaching the Grand Prix Final, Jin - who finished fourth at PyeongChang 2018 - insists that there is plenty more to come from him this season.
Speaking to ISU.org, he said, "My performance was OK, but still not as good as I have been training.
"Last year there was no Cup of China and I am very happy that the event came back. The main colour of the rink is red, like the spicy colour of Chongqing and that motivated me a lot."
Yan made it a China one-two with Matteo Rizzo completing the podium places.
Jin jumps to home win
The standard of skating was higher than in Friday's fall-ridden short program.
After a hugely disappointing short program left him down in 11th place, Junhwan Cha at least gave a hint of what he can do in the free skate.
His quad toe loop and quad Salchow were far from perfect in a routine which has been tweaked since Skate America, but this was a good recovery from the Korean who scored 152.86 for a total of 222.26 to finish in sixth place.
Keegan Messing certainly did not lack for enthusiasm in his crowd-pleasing free skate to 'November Rain' by Guns N' Roses and he looked exhausted after falling on his closing triple Axel.
His jumping was patchy throughout, starting with a triple Lutz instead of a quad, and putting hands down twice on quad toe loop attempts.
But the Canadian still scored 160.56 for a total of 237.36 and fourth place.
After landing a quad Salchow-double toe loop combination at the start of his routine, Keiji Tanaka's jumping deteriorated somewhat.
The Japanese put a hand down on a quad toe loop and singled what should have been a triple Axel, but his free skate score of 158.98 saw him move up to fifth with a total of 233.62.
Tanaka needed a podium finish to be in with a chance of making the Grand Prix Final after his third place at Skate America.
But Jin was much the best in the free skate.
He started with a quad Lutz and a quad toe loop-double toe loop combination before doubling a quad toe loop.
The rest of the routine was very good indeed with a flawless triple Axel the highlight as he scored 176.10 to take his total to 261.53 and secure his biggest win since the 2018 Four Continents.
For Yan, this was a spectacular comeback after a year off the circuit.
Having led after the short program, the 2013 Cup of China winner opened with a triple Axel-triple toe loop combination and showed he has plenty to offer.
Despite a couple of jumping errors late on, the 23-year-old scored 160.56 to take second place in the free skate and overall.
He told ISU.org, "I want to thank the Chinese team that they gave me the chance to come back.
"My performance was normal, but I didn’t have the highest degree of difficulty. I'm a bit surprised that I can be on the podium with triple jumps. I came here like a rookie skater."
Rizzo was last to go after taking third in the short program.
The Italian skated well but a fall on a triple Axel saw him finish just behind Messing in the free skate with 160.16.
That was enough for the reigning Universiade champion to take third overall with a total of 241.88.