Djokovic will replace Rafael Nadal, the best player in the world on Monday after missing two years.
The 31-year-old has long been five months since he failed to become the 22-year-old world-at least 12 years – after the French Open quarter-final.
Since then, he won the Wimbledon and the US Open, with Grand Slam, 14, winning 20 consecutive matches for the sixth, and 29 of the 30 matches the latest.
"We're back on what I've been through last year, it's a great victory," said Djokovic after winning the quarter-finals of the Champions League with Bosnia-Herzegovina's Damir Dzumhur 6-1, 1.
"I am very happy and happy, five months ago, it was very poor and we respect the level and how I played and felt the court.
"I think I have the ability to talk about a lot of issues during the season, and I hope to finish with the number 1"
The success achieved by Thursday means Djokovic has also increased his impressive form of winning 30, coming from the 29th of July 2015.
The fourth quarter of Paris, coming along with Marin Cilic on Friday, was promised to return to the top leadership when Nadal returned from Paris with a hamstring injury on Wednesday.
"It's not the end of the season, Rafa clearly struggled with injuries since he opened the US Open, but the tournament is still here," added Djokovic.
"Roger Federer is the competition, Rafa is in the competition, depending on the person who is playing at the ATP Final in London, as I said, it can not be too complicated."
Delicatess, the fifth edition, confirmed his quarter-finals in 7-6 (7/5), 6-4 defeat to Grigor Dimitrov.
& # 39; We are all tired '& # 39;
Cilic has recruited 29 people who have been successful in overcoming the last eight years of the French capital in the third consecutive year.
The victory also promoted Croatia's hopes to the ATP final in London in November 11.
"I am very close to London, to count my place," said Cilic, who is part of the Croatia squad for the Davis Cup final at the end of the month.
"The next game against Novak will be another great challenge" (It will be) to play again. "
Cilic, who beat Djokovic only twice in 17 games, ended the ATP Final Champion Dimitrov.
Djokovic and Cilic joined the quarterfinals of Karen Khachanov who saved two weeks ahead of John Isner's 6th, 6-7 (9/11), 7-6 (10/8).
Russia will play next match Alexander Zverev after Germany's fourth German winner Diego Schwartzman beat Argentina 6-4, 6-2.
On Thursday, Federer met with Fabio Fognini, who played for the Italian side in the 8th position.
Federer has enjoyed a third consecutive year when Raonic sustained a hamstring injury.
So far this week, there were five retirement and two improvements as the long-term activity started biting.
"We are all very tired," said Schwartzman, 19, who was on the road for more than two months. "It is not easy."