Watching Djokovic has become a live-action demonstration of a tennis player figuring out his limits from match to match and week to week.

Novak Djokovic rallied in the second set from 4-1 down to close out American Sebastian Korda 6-3, 7-6 (4) to advance to the Miami Open semifinals, while women's No. 1 seed Aryna Sabalenka breezed into her first Miami final.

Novak Djokovic reached the semi-finals of the Miami Open with a hard-fought 6-3 7-6 (4) win in his delayed last-eight clash with Sebastian Korda. The 24-time grand slam champion trailed 5-2 in the second set before hitting back to secure victory in a tie-break.