The Serb will lose his position if he fails to reach the final of the Association of Tennis Professionals (ATP) Masters 1000 event and closest rival Andy Murray wins the title in the French capital.

After admitting he has struggled for motivation since winning a maiden French Open singles crown earlier this year, Djokovic claims to be desperate to maintain his 122-week grip on the summit of the sport.

He began well with a straightforward 6-3, 6-4 victory over an opponent ranked 34th in the world.

A break in the sixth game proved enough to take for first set before another crucial win on his opponent's serve at 4-4 in the second proved crucial in a victory which took just one hour and 20 minutes.

Bulgaria's 14th seed Grigor Dmitrov lies in wait in round three after his Cypriot opponent Marcos Baghdatis pulled-out through injury having lost the first set 6-3.

Wimbledon champion Murray, the world number two who claimed a third title in as many weeks in Vienna on Sunday (October 30), also began with a victory.

He triumphed 6-3, 6-7, 7-5 over Spaniard Fernando Verdasco.

Japan's fifth seed Kei Nishikori claimed his 300th career win with a 6-2, 7-5 victory against Serbian Viktor Troicki.

Belgium's eighth seed David Goffin also progressed with a 7-6, 6-3 win over Frenchman Nicolas Mahut.

There was plenty of home success on the third day of action at the, however, with France triumphing in three Franco-Spanish duels.

Gilles Simon beat Roberto Butista Agut, 2-6, 6-1, 7-6, Jo-Wilfried Tsonga overcame Albert Ramos-Vinolas 6-3, 6-4 and Lucas Pouille got the better of Feliciano Lopez, 6-7, 6-3, 6-4.

Ninth-rated Marin Cilic also won an all-Croatian tussle 7-6, 6-2 over Ivo Karlovic.