Novak Djokovic claimed a record seventh year-end number one ranking by overcoming Poland's Hubert Hurkacz to reach the Paris Masters final.
Hurkacz, 24, won the semi-final's first set but was outplayed in the second.
In a nervy deciding set, Djokovic, 34, won on his second match point to prevail 3-6 6-0 7-6 (7-5).
That victory meant the Serb surpassed Pete Sampras's record for the most year-end rankings and now has two more than Roger Federer and Rafael Nadal.
Djokovic will contest his seventh Paris Masters final on Sunday, having won five of his previous six.