England's Luke Humphries defeated teenager Luke Littler 7-4 in a gripping final at Alexandra Palace to win his first PDC World Championship title.
Littler, 16, was aiming to become darts' youngest ever world champion after a remarkable run to the final.
But Humphries, the pre-event favourite who became world number one on Tuesday, saw off his challenge to claim the £500,000 first prize.
Trailing 4-2, the 28-year-old won five consecutive sets to close out victory.
“I could not put into words how great this feels,” Humphries told Sky Sports.
“In the back of my mind throughout today, I was thinking ‘get this one now because he's going to dominate world darts soon'. He's an incredible player. When I was on the brink of winning there, he was relentless.
“That double eight [to win], my hands were shaking like mad and it just fell in for me. I'm world champion and world number one and I can't ask for more.”
Humphries has now won four of the past five major televised tournaments in the PDC (Professional Darts Corporation).
Littler's progress on his World Championship debut has captured the public's imagination in the past three weeks and he produced another exceptional, composed performance in the final.
However, Humphries' brilliance ensured the youngster fell just short of completing what would have been an amazing sporting fairytale.
Littler said: “The one negative was I lost too many legs on my throw, so Luke would break me, then hold and I'd be 2-0 down [in the set].
“Fair play to Luke, he deserves it.
“I've got to the final, I might not get to another final for the next five to 10 years, we don't know, but I can say I'm a runner-up and now I just want to go and win it,” added Littler, who has climbed more than 130 places into the world's top 32.
Humphries appeared to settle the quicker of the two finalists as the first four sets were shared, with Littler finding his range by landing finishes of 142 and 120 in the second.
The teenager took the fifth to lead for the first time and appeared to have his more experienced opponent on the ropes when he raced through the sixth set.
But Humphries gained impetus from a 170 finish at the start of the seventh and took advantage when Littler missed a double attempt for a 5-2 lead, going on to level the match with a 121 checkout on the bull before moving clear.
Littler hit a 170 checkout of his own in the 10th set, but Humphries held his nerve, sinking to his knees after landing a shot at double eight to clinch the biggest win of his career.
Humphries hit 23 maximums and averaged 103.67 in the final, compared with Littler's 13 180s and 101.13 average.
Humphries reaches the pinnacle
Crewe-based Humphries entered the World Championship as the sport's in-form player, having broken his major trophy duck with wins at the World Grand Prix, the Grand Slam and Players Championship Finals.
At Alexandra Palace, his route to the final was far from straightforward.
He twice needed to win deciding sets – and a sudden death deciding leg in the case of his last-16 tie against Joe Cullen – and it was only in his quarter-final and semi-final wins over Dave Chisnall and Scott Williams respectively that Humphries fully demonstrated his dominant recent form.
Wednesday's victory over Littler was his 19th win in a row and, after progressing steadily over the past few years, it firmly establishes him at the top of his sport as both world champion and the world number one.
One step away for teen star Littler
Littler has earned £200,000 for his efforts at Alexandra Palace – a sensational financial return for a teenager who only finished his GCSE exams a few months ago.
His run to the final is even more remarkable given Littler, the PDC world youth champion who threw his first darts when he was 18 months old, had only played four senior matches at PDC premier events before the start of the tournament.
His ambition entering the competition was to win one match and he became the youngest player to do so at a World Championship when he beat Christian Kist in the first round.
He defeated two former PDC world champions, Raymond van Barneveld and Rob Cross, and won 25 of the 31 sets he played on his way to becoming the youngest ever world darts finalist.
Even more impressive than his fantastic ability on the oche has been the way he has dealt with the incredible interest in him and his story as the tournament has progressed.
As well as additional media commitments, Littler was invited to Premier League football matches at Tottenham and Arsenal and has received messages of support from stars across the sporting landscape.
Unknown outside darts when the World Championship began on 15 December, Littler has ended it catapulted into stardom; trending on social media, attracting a huge fanbase and dominating the news agenda for broadcasters, written and online media.
Sky Sports reported a peak viewing figure in excess of 2.3m for Littler's semi-final win over Cross, a record for Sky's World Championship coverage, and it seems unthinkable that number would not have been surpassed on Wednesday.
— CutC by bbc.com