After winning the ATP Finals, Stefanos Tsitsipas feels grand slam success is not far away.
Stefanos Tsitsipas and Dominic Thiem served up a thriller at the O2 Arena and it was the Greek who came out on top to make history.
Rafael Nadal is second only to Roger Federer on the men's grand slam all-time list - but his uncle says he could have been clear at the top.
There will be a first-time ATP Finals champion on Sunday after Dominic Thiem ended Alexander Zverev's reign in London.
Defeating Roger Federer in the ATP Finals had Stefanos Tsitsipas acknowledging the scale of his achievement.
A famous win for Stefanos Tsitsipas saw off Roger Federer, but the Swiss star attempted to take some positives while admitting his errors.
Former world number four and 2010 Wimbledon Tomas Berdych says his body will not allow him to continue playing at the highest level.
Going up against Roger Federer is the biggest honour for Stefanos Tsitsipas, who overcame the former world number one in the ATP Finals.
Stefanos Tsitsipas set up an ATP Finals showdown with Dominic Thiem or defending champion Alexander Zverev by beating Roger Federer.
Matching Roger Federer and Novak Djokovic for year-end number one rankings pleased Rafael Nadal.