Grigor Dimitrov claimed the biggest title of his career by edging a three-set thriller with David Goffin to win the ATP Finals in London.
For years Dimitrov has struggled to deliver on his supreme technical talent but the Bulgarian may finally be living up to the hype after he beat Goffin 7-5 4-6 6-3 at The O2.
Fans may have hoped for a re-run here of Roger Federer versus Rafael Nadal, the veteran grandees who dominated the sport in 2017, but Dimitrov and Goffin offered an enthralling finale and perhaps a glimpse of the future.
Dimitrov becomes the first ATP Finals debutant since Alex Corretja in 1998 to lift the trophy and it was the first time in the competition's 47-year history that two first-timers had made the final.
After the last point, he dropped face down, flat on the court before embracing his team and coach Daniel Vallverdu, who was once in charge of a young Andy Murray.
"It has been a tremendous two weeks for me," Dimitrov said. "It's such an honour to play here. This week has been one of the best I've ever had."
Both aged 26, Dimitrov and Goffin are hardly fledglings on the tour but there is still time for each to enjoy greater success at major tournaments. Goffin has never gone further than the last eight at a grand slam while Dimitrov's best is two semi-finals.
Dimitrov, in particular, looks now to be a leading contender behind Nadal and Federer, and he will rise to world number three when the rankings update on Monday.
He also pockets the champion's cheque for $1.2million to take his total haul for the week to $2,549,000.
Goffin saw off both Nadal, who was hampered by injury, and Federer en route to the final. The Belgian will now head into next week's Davis Cup final against France brimming with confidence.
David Beckham and Patrick Stewart were among a 17,800 capacity crowd, who were treated to another pulsating encounter in keeping with this year's matches.
For all the star absentees including Murray, Novak Djokovic, Stan Wawrinka and, from day two onwards, Nadal, 11 of the 15 singles matches went to deciding sets.
Goffin's 6-0 6-2 group-stage loss to Dimitrov was one of the few lopsided affairs but he had more games on the board after 19 minutes here than in the entirety of that encounter.
Serving to stay in the first set at 6-5, Goffin saved four set points and then had the chance to close out the game but instead double-faulted.
A wayward forehand gave Dimitrov set point number five and this time he made no mistake as another nervous Goffin forehand hit the net.
The second set turned midway through as Dimitrov missed a break point before Goffin converted his, a 95 mile-per-hour forehand into the corner breaking the Dimitrov serve. Goffin served out to love to force a decider.
With a 22-5 record this year, no man has been better in deciding sets than Goffin and he should have secured an early advantage but failed to finish four break points.
They proved costly misses as a backhand skewed just wide put Dimitrov 4-2 clear before a reaction volley, looping lob and whipped backhand soon set up three championship points.
Goffin saved all three to make Dimitrov serve out, which he finally did with his opponent's help as a simple volley dropped into the net.
Earlier in the day, Jamie Murray's former partner John Peers won the doubles title alongside Henri Kontinen. They beat Marcelo Melo and Lukasz Kubot, the world's top-ranked pair, 6-4 6-2.