World no. 1 Novak Djokovic defeated Lleyton Hewitt in four sets with such gutsy display of stubbornness that was not ready to give up and certainly not enough to derail Novak Djokovic’s title defense at the Australian Open.

Hewitt looked down and out at two sets but he stormed back to take the third round and then to the fourth, hopeful to equalize the defending champion but to no avail.

The reigning champion won over the 30-year-old Australian 6-1 6-3 4-6 6-3 in nearly three hours.

Djokovic was cruising after winning the first two sets, but he then had to withstand a powerful Hewitt fightback, dropping his first set of the tournament before completing victory.

The 24 year old took full advantage, three breaks handing him the first set and three more moving him two sets up.

He won the first three games of the third, it seemed just a matter of time before victory was secured.

Djokovic took full advantage, three breaks handing him the first set and three more moving him two sets up.

The Serb withstood a break point to lead 2-1 in the fourth and finally picked up a break himself to move 4-2 ahead but, after Hewitt had held his serve, Djokovic completed a hard-fought victory.

The top seed will be playing against David Ferrer in the quarter-finals.