rewrite this title Watch shock moment Djokovic retires injured against Zverev in 'great shame'

Summarize this content to 2000 words in 6 paragraphs “Watch the shock moment Novak Djokovic retires injured against Alexander Zverev in what is a u0027great shameu0027 in their Australian Open semi-final in Melbourne. Stream the Australian Open live and on-demand on discovery+”