On Saturday, fans saw Novak Djokovic involved in yet another huge upset, as he cruised to a 6-3 6-3 over Rafael Nadal to remain on course to win his fourth ATP World Tour Finals title in a row.

The Serbian has looked undefeatable this year and even when faced against an opponent such as Rafeal Nadal in the quarter finals, he breezed past him as his game appeared more assured and quite simply stronger, throughout. 

Nadal has been seen as the one to beat at the French Open, for years, as he claimed the title every year since 2005, except on one occasion in 2009' losing out to Robin Soderling in 4th round.

Although the victor doesn't feel unbeatable, himself, his oppenent on the other disagrees, "Novak for the moment is almost unbeatable. As I've said before the only thing you can do it congratulate him.

Dream final here @ATPWorldTour finals #Federer v #NovakDjokovic can Fed really beat Novak 2 x in a week? Tough ask, we will soon see— Pat Cash (@TheRealPatCash) November 22, 201

Roger #Federer set up a World Tour Finals showdown with Novak #Djokovic on Sunday. Looking forward to this! #ATPWorldTourFinals #Tennis— Juliet Bawuah (@julietbawuah) November 21, 2015

The win sees the world number one, reign in on records that have been held by Nadal and Roger Federer for years and although it might seems a long shot, right now, it would be wrong to say he couldn't achieve it – especially when his in this kind of form.