The Frenchman climbed seven places in the ATP rankings to end the year in 44th place, with Spain's Pablo Carreno Busta slipping out of the top 50.
With the ATP Tour calendar coming to an end last week with the World Tour Finals in London, the top 24 remains unchanged with Julien Benneteau moving up a place to 25th.
Novak Djokovic had ensured his second number one finish in three years at the O2 Arena showpiece, prior to winning the Finals on Sunday when Roger Federer pulled out.
The two had been due to face off in the final of the competition, but the Swiss was unable to feature due to injury.
Djokovic had guaranteed his spot at the summit with his 6-2 6-2 win over Tomas Berdych in Friday's final group match, with Federer and Rafael Nadal forced to settle for second and third place respectively.
Further down the standings, Dudi Sela's run to the final in Helsinki helped him move 14 places up to 97th, while Viktor Troicki rounded off a difficult 12 months, which saw him banned due to doping issues, by moving up five places to 99th.
The women's final rankings of the year saw only one change in the top 50, with Roberta Vinci and Timea Bacsinszky swapping places in 47th and 48th respectively.
Serena Williams - who had been ensured of her number one spot at the WTA Finals last month - topped the rankings, with Maria Sharapova and Simona Halep following in second and third.