The Bulgarian was stretched to the limit in the two and a half hour contest at the O2 Arena in London before victory was secured with a botched volley into the net from the Belgian on championship point.
Dimitrov becomes the first player outside the Big Four to prevail at the year-end event since Nikolay Davydenko in 2009. He will finish the year as the world number three and the title neatly bookends a season where he triumphed in Brisbane in January.
Goffin, meanwhile, heads to Belgium where he will be aiming to exorcise the demons of 2015 when his nation hosts France in the Davis Cup final.
Nerves could be forgiven considering it was the first time either men had competed in a final of such magnitude and both struggled behind their own deal early on.
Goffin broke his opponent in the very first service game with a blistering forehand return winner before Dimitrov’s endeavor paid dividends to recover the break. The Belgian then mustered three break points on the 26-year-old’s serve and converted with a sumptuous backhand passing shot.
Goffin’s forehand was working a treat, frequently troubling the Bulgarian from inside-out, but his concentration wavered in the eighth game of the set. After battling back from 0-30 with a couple of serve and volleys he was coaxed into a forehand error with Dimitrov building in momentum.
The ship was steadied but Goffin found himself backed into a corner having to serve to force a tie-break and Dimitrov began to carve out openings. Four set points slipped through the fingers of the 26-year-old but when the fifth arrived he sensed his opportunity. Measuring groundstrokes, he prompted an error from Goffin and the first set swung the way of the Bulgarian.
The second set whizzed through in contrast to the opener and Dimitrov very nearly grabbed the vital break with a line licking forehand in the sixth game. The lines judge felt the ball had nicked the far side line but umpire Mohamed Lahyani overruled and Hawkeye came to Goffin’s aid.
Instead the Belgian found an extra gear, transitioning seamlessly from defence to attack in the very next game to break, and he had set two tied up inside 38 minutes.
And he was well-positioned to start the deciding frame in supreme fashion when he had Dimitrov against the ropes. Two break points came and gone and it was only after eight minutes that Dimitrov finally confirmed the hold.
The shotmaking under such high pressure from both players was dazzling and with the rallies lengthening the magnitude of the moment was felt around the arena.
Deuce games were frequent and it was the sixth game that proved the turning point for Dimitrov. After squandering one break point he could not believe his luck when Goffin saw a backhand fly wide on a second break point.
Victory was within grasp as the Bulgarian fashioned three championship points on Goffin’s serve. The never-say-die fighting spirit of the Belgian shone through, however, as he reeled off five straight points to force Dimitrov to serve for the title.
He duly obliged, sinking to the court in a state of euphoria. His fourth title of 2017 proved the most magical.