It was Advani's 10th individual World title and his third of the year in different formats of the game, having won the World 6-Red Snooker and the World Team Billiards titles earlier.
"I'm in 11th heaven! I returned to India to focus on this very event and it has paid off. Gilchrist was the most dangerous competitor of the tournament and in a dream final. I am happy with the way I performed.
"The job is only half done. I have to now focus on the longer format and try for a double. I have a match at noon Sunday, so celebrations will have to wait, but no complaints," said Advani after the final.
"I'm in 11th heaven! I returned to India to focus on this very event"
Advani, who skipped two seasons of billiards for a stint on the professional snooker tour, trailed 1-2, but won five frames on the trot to regain the title he had last won in 2012.
In winning his 10th individual World title, Advani vindicated his decision earlier this year to give up his professional status in snooker to pursue his billiards career.
Advani thus avenged his 2-3 defeat in the league phase to Gilchrist, the 46-year old England-born Singapore resident who has three World titles to his credit.
Gilchrist was quick off the blocks as breaks of 144 in the first frame and 74 in the third gave him a 2-1 lead, but Advani surged back to take the next two frames and heading into the break leading 3-2.
On resumption, it was Advani all the way with Gilchrist struggling to have a say in the proceedings. The decisive moment came when Gilchrist, needing 44 to win the eighth frame, lost position after crafting a run of 39 to lead 145-77. Advani seized the chance to make an unfinished 77 to wrap up the match.
Final (best-of-11): Pankaj Advani (India) bt Peter Gilchrist (Singapore) 6-2: 23-151 (145unf), 151 (127)-16, 116-150, 151(108unf)-104, 150(150unf)-0, 151(118)-58, 150-4, 150(77unf)-145(104). Semi-finals (best-of-9): Advani bt Sourav Kothari (India) 5-2. Gilchrist bt Robert Hall (England) 5-3.