MELBOURNE, Jan 24 (Reuters) - ‌Jannik Sinner suffered cramp in extreme heat ‌and lost his first set since October ‌but the Australian Open defending champion battled through to the fourth round with a gutsy 4-6 6-3 6-4 6-4 win ‍over American Eliot Spizzirri on ‍Saturday.

In extraordinary scenes at ‌Rod Laver Arena, the Italian limped over to ‍his players' ​box in desperation midway through the match and was told by coach ⁠Darren Cahill to walk through the rest ‌of the third set, if necessary, to get to a ⁠break.