Novak Djokovic kept alive his slim hopes of regaining top spot in the world rankings by reaching the Paris Masters semi-finals with a convincing victory over Stanislas Wawrinka.

The second-seeded Serbian took just 82 minutes to claim a 6-1 6-4 result and extend his winning run to 15 matches.

Djokovic was knocked off top spot by Rafael Nadal last month and will need to at least reach Sunday's final to stand an outside chance of finishing the year as world number one.

However, he showed he is on form on Friday, winning 71 per cent of points on his first serve and breaking his Swiss opponent three times.

"[I am] very satisfied with [my] great intensity from the start of the match," Djokovic told the ATP Tour website afterwards.

"I tried to be as aggressive as possible when I have a shorter ball, but still get as many returns back and serve efficiently."

"[I am] very satisfied with [my] great intensity from the start of the match" - Djokovic 

Djokovic will now face Roger Federer in Saturday's semis after the fifth seed dug deep to see off Argentina's Juan Martin del Potro 6-3 4-6 6-3.

In a match lasting one hour and 44 minutes, it was Federer's serve which eventually proved the difference between the two men, the Swiss landing 82 per cent of his first service points against the fourth seed.

In an intriguing twist, all eight quarter-finalists in Paris - Djokovic, Nadal, Federer, Del Potro, Wawrinka, Richard Gasquet, David Ferrer and Tomas Berdych - have also qualified for next week's Barclays ATP World Tour Finals in London.