Sinner to halt Djokovic's potential farewell or will unthinkable happen again?

At 39-years-old, 23-time Grand Slam champion Novak Djokovic is raging against the dying of the light as far as his professional career is concerned. But rage he is most certainly doing. 

The combustible, often-controversial Serb has appeared to struggle with fatigue through each of his last three encounters at this year's Wimbledon championships, but somehow has hung in and dug out victories seemingly just within the nick of time.