The former world number slipped outside top four in the latest ATP Tour rankings for the first time since 2007.
Johannesburg: Serbian tennis maestro Novak Djokovic has slipped by one place to move outside top four in the latest ATP Tour rankings for the first time since 2007.
The former world number one, who had earlier this month announced that he would not play again this season due to an elbow injury, is now standing at the fifth spot while Switzerland's Stan Wawrinka moved up to the fourth place.
Meanwhile, the biggest move is made by Alexander Zverev as he broke into the top 10 for the first time. The German tennis player climbed up by three places to the eighth spot, Sport24 reported.
Britain tennis maestro Andy Murray continues to remain at the top spot and maintains the lead of just 285 points ahead of 15-time Grand Slam champion Rafael Nadal.
Latest Top 20 ATP Tour rankings:
1. Andy Murray
2. Rafael Nadal
3. Roger Federer
4. Stan Wawrinka
5. Novak Djokovic
6. Marin Cilic
7. Dominic Thiem
8. Kei Nishikori
9. Milos Raonic
10. Alexander Zverev