Grigor Dimitrov beat David Goffin 7-5, 4-6, 6-3 to win the 2017 ATP World Tour Finals title at the O2 Arena in London on Sunday.
The Bulgarian got off to a slow start and was 4-2 down in the opening set before recovering to take it 7-5.
However, Goffin hit back in the second set to force a decider, but Dimitrov kept his nerve to take it 6-3 and claim the biggest title of his career so far.
Sunday's final was the first between two players who had never reached a Grand Slam final before, as noted by Stuart Fraser at The Times:
The first set was an exciting affair with both players struggling on serve initially but also showing flashes of real quality.
Goffin got off to a great start breaking Dimitrov straight away, but the Bulgarian hit straight back to level it up.
Live Tennis showed how difficult it was for either man to hold serve in the opening stages:
Goffin finally held at 3-1 as both players started to settle down after a nervy start. Tennis commentator David Law neatly showed why the Belgian was ahead early on:
However, the momentum swung back towards Dimitrov towards the end of the set, the Bulgarian getting the break back at 4-4 and then holding to make it 5-4 after raising his level.
Tennis TV showed just how well Dimitrov was starting to play:
Dimitrov forced Goffin to serve to stay in the set again at 6-5 and had five set points before the pressure finally told, the Belgian netting a forehand as his opponent took the first set 7-5.
The second set was much tighter with Goffin responding, holding both of his opening two service games to love.
Dimitrov finally forced a break point at 3-2, but Goffin saved it with a superb backhand that was originally called out before being overruled. Live Tennis showed it was a great call:
It was to prove a turning point, Goffin then breaking for 4-3 and holding serve to take it 6-4 and force a deciding set.
Greg Rusedski had a theory as to why Dimitrov had been pegged back:
Both players had break points at the start of the third set but were unable to convert until Dimitrov finally broke to make it 4-2, Goffin drifting a backhand wide.
In a dramatic finish, Goffin then saved three match points to force Dimitrov to serve it out, and despite the Belgian's best efforts, a sliced volley into the net gave the Bulgarian the victory.
Tennis TV captured the moment of victory:
Tennis writer Jose Morgado also provided the year-end rankings, with Dimitrov now third in the world:
It's a huge win for Dimitrov, who just had the edge when it mattered, in a tightly contested final, and ends the year in style and will hope to build on this victory next season starting at the Australian Open in January.