Roger Federer claimed the seventh title of a spectacular 2017 by beating Juan Martin del Potro over three sets to win the eighth Swiss Indoors crown of his career.
Federer had to work hard on Sunday before dispatching Del Potro 6-7 6-4 6-3, making amends for two final defeats to the Argentine in Basel in 2012 and 2013.
After a thrilling contest that saw the pair share the opening two sets, a tiring Del Potro could not keep up in the deciding set and, having stolen a break in the opening game, Federer roared back to win four games in succession to set up the win.
After the match Federer confirmed he would make a late decision on his participation at next week's Paris Masters and organisers later confirmed he would not be in the field for the final Masters 1000 event of the year, all but ending his hopes of ending the year as the world no 1.
In truth it was always unlikely and the 19-time Grand Slam champion will more realistically have his sights set on a first season-end title since 2011.
For Del Potro, though, it is just a second defeat from his last 14 matches - both coming against Federer - but his run to the Basel final means he is in contention for a place at The O2 himself although he will need to make at least the semi-final.
Back in Basel, it was Del Potro who somehow claimed the opening set, defying 65 minutes of Federer dominance to take it on the tie-break.
Federer broke in the first game of the match and forced countless opportunities thereafter, before finally breaking again to lead 5-4. But, as he had done in the second game of the set, Del Potro broke back immediately as the opener went the distance.
The world No 2 seized control again, powering to a 3-0 lead in the tie-break only to see Del Potro reel off six points in succession to force three set points. Federer saved the first two but a searing first serve clinched the set for the Argentine.
In a role reversal of the first set, Del Potro was the aggressor in the second, bossing the first half of the set and forcing the early break opportunity, which Federer withstood.
As he began to bend the match to his will, Federer came into the net with more regularity and it paid dividends as he forced two set points on the Del Potro serve at 5-4 in front. The first went begging, but when Del Potro fired a forehand long Federer had the set.
With a raucous St Jakobshalle behind him, Federer looked to have made the breakthrough, but Del Potro had other ideas, capitalising on an uncharacteristic mistake from the Swiss to break in the first game of the third set only to hand the break straight back.
Del Potro's levels began to drop and having held serve comfortably, Federer forced three break points for a 3-1 lead, which he took at the third time of asking.
Federer closed out the match with the minimum of fuss having been made to work hard by an opponent who always tends to bring out his best, and his reward was a 95th career title now just seven behind Jimmy Connors' all-time record.
Meanwhile in Sunday's other final, Lucas Pouille won the battle of the Frenchmen with a dominant 6-1 6-4 victory over Jo-Wilfried Tsonga to claim the Erste Bank Open.
Pouille, who had battled from a set down to beat Kyle Edmund in Saturday's semi-final in Vienna, had won three previous titles in his career, but all at 250 level, so his success over Tsonga represented the biggest tournament victory of his career.
It is also a third title of 2017 for Pouille, on a third different surface, adding this week's indoor crown to the trophies claimed on clay and grass and confirming his status as one of the game's most talented young stars.
However, like Del Potro, Tsonga has catapulted himself into the race for the ATP Finals after an impressive couple of weeks and will head to Paris as a former champion and with a chance to keep his season going, while Pouille could also make it.
Pouille, Tsonga and Del Potro will all need stellar weeks in Paris but with Federer withdrawing and doubts over Rafael Nadal's participation, then the window of opportunity would open for all three if their form this week is anything to go by.
The action continues next week with the Paris Masters on Sky Sports throughout the week, beginning on Monday from 10am on Sky Sports Arena and Sky Sports Main Event
The Next Gen ATP Finals in Milan and season-ending extravaganza ATP Finals at London's O2 in November end another memorable year which will be covered via our website sky.mnosports.com/tennis with live blogs and updates as the season reaches its climax
On the move? Head to our app for mobile devices and iPad, or follow our Twitter account @SkySportsTennis to join in the conversation. Who will win the World Tour Finals this year? Have your say...