MELBOURNE, Jan 24 (Reuters) - Jannik Sinner battled back from ‌the brink of a cramp-induced breakdown to keep his Australian Open title defence alive after extreme heat brought play to a halt on baking ‌outdoor courts at Melbourne Park.

In a dramatic third-round match, Italian Sinner lost his first set since October against inspired American Eliot Spizzirri and ‌was a limping wreck under a blazing sun at Rod Laver Arena.