Tennis world number one Novak Djokovic mounted a legal challenge to being refused entry to Australia on Saturday.Arguing he'd been given a medical exemption from vaccination because he'd been infected by Covid-19 last month.WATCH MORE: https://thestartv.com/c/newsSUBSCRIBE: https://cutt.ly/TheStarLIKE: https://fb.com/TheStarOnline