THE ALL ENGLAND CLUB, London — Novak Djokovic is not done.The 39-year-old, seven-time Wimbledon champion came through a five-set, five-hour epic Tuesday on Centre Court to defeat Félix Auger-Aliassime 7-6(10), 3-6, 6-3, 6-7(4), 7-6(4) and advance to the semifinals, six minutes before the 11 p.m. curfew.There, he will face his toughest hurdle yet on the path to a record 25th Grand Slam title in top-seeded Jannik Sinner, and how much this match has taken out of Djokovic will be crucial to deciding the result of that match.Despite not looking his best — compared to his usual jaw-dropping level, that is — Sinner hasn’t dropped a set since his five-set, first-round win over Serbia’s Miomir Kecmanović.Djokovic’s path hasn’t been as clean, but until he met Auger-Aliassime, he hadn’t been pushed as hard as he could’ve been. Djokovic dropped a set in three of the four other matches he’s played at the All England Club this year, but Canada’s No. 3 seed provided the most dramatic test, extending Djokovic into finding his best tennis when his body was screaming at its loudest, as both men covered every inch of the Centre Court grass in the match’s final stages.It started with a stumble.In the first set, Djokovic was serving at 4-4 when he hit a backhand down the line and pulled up. The 39-year-old waved to his team immediately and indicated that he would need attention, before retreating to the back of the court and stretching the bottom of his leg out.He was able to hold serve to love for 5-4, but at the change of ends took a medical timeout and received treatment on his ankle and calf, before returning to the court.Seemingly revived in the immediate aftermath, Djokovic forced two set points on the Auger-Aliassime serve in the next game. But the Canadian dug in to hold and Djokovic was still grimacing in pain in between points. Djokovic saved a break point himself in the next game then, almost as if nothing had ever happened at all, won the tiebreak.