Novak Djokovic and Jannik Sinner will once again meet in the Wimbledon semi-finals after contrasting tournaments so far.

Jannik Sinner (left) had won five matches in a row against Novak Djokovic before this year's Australain Open You wouldn't normally expect a 39-year-old who had just spent five hours and 15 minutes on court to challenge the world number one in a Wimbledon semi-final. But this is Novak Djokovic we're talking about - and he is, in the best way possible, not normal. On Friday, Djokovic will face world number one and defending champion Jannik Sinner for a place in Sunday's final. They met at this stage last year, with Sinner winning in straight sets despite having an elbow injury and Djokovic struggling after a fall in his previous round. This time around, Sinner is injury-free and has not dropped a set after his opening match went the distance. However, Djokovic needed a medical timeout after tweaking what appeared to be his left calf early in his epic quarter-final against Felix Auger-Aliassime - and then ended up battling until almost 11pm at night to see off the Canadian. Age, time on court and the head-to-head are all in Sinner's favour, but Djokovic won their last meeting at this stage of the Australian Open and cannot be counted out.