Britain’s Andy Murray celebrated his rise to world number one by beating American John Isner 6-3, 6-7 (4-7), 6-4 to win his first Paris Masters title.
After double-faulting on the first point of the game, Murray soon clicked into gear, breaking for a 4-2 lead.
He showed watertight defence to close the door on Isner when the American created two break points of his own in the next game.
Murray managed only six points on his opponent’s serve in the set, but that was enough to take it in 35 minutes.
The unseeded Isner continued to put pressure on Murray in the second, showing an increasing deftness at the net to take the second set to a tie-break.
The 6ft 8inch 31-year-old had too much for the Scot in the decider, serving imperiously to take the breaker 7-4.
Twice in Isner’s first two service games of the third set Murray saw break points snatched away by his opponent’s huge serve.
But Murray was not to be denied, and he finally forced a break at 5-4, firing in a rapid backhand that Isner could only slug into the net, to take the third set and the match.
The victory was Murray’s sixth ATP title of a memorable 2016.
The Scot, 29, also added his second Olympic and Wimbledon titles on his way to the top of the rankings.
He will be officially confirmed on Monday as Britain’s first singles number one since computerised rankings were introduced in 1973.
Murray’s ascent to the top of world tennis was made easy by Milos Raonic’s withdrawal from Saturday’s semi-final with a leg injury.
Former world number one, Novak Djokovic had lost the position after he was beaten by Marin Cilic in the quarter finals.
Murray now heads to the season-ending World Tour Finals as top seed for the first time.
However, if Djokovic wins every match at the Finals he will reclaim the top ranking he held for an overall 203 weeks.
The draw for that competition takes place tomorrow at 15:00 GMT.
