Serbia's Novak Djokovic [Source: Reuters]

Novak Djokovic was dragged into a dogfight by talented teenager Dino Prizmic and had to dig deep to open his Australian Open title defence with a 6-2 6-7(5) 6-3 6-4 victory in the first round.

At a shade over four hours, it was Djokovic’s longest first-round match at a major and he heaped praise on the Croatian qualifier for his performance on his Grand Slam debut.

The Serbian, who played his first Australian Open a few months before the Croatian qualifier was born in 2005, initially looked fully in control of the contest on the Rod Laver Arena court where he has won 10 of his 24 Grand Slam titles.

Prizmic had already shown glimpses of the weapons he possesses and broke the top seed with a brilliant crosscourt winner early in the second set, forcing Djokovic to raise his game to break straight back.

The 18-year-old world number 178, who need a medical timeout to get some strapping on his thigh early in the match, was a man transformed, however, and kept up his level to even up the contest in the tiebreak.

That merely set the tone for an enthralling third set in which Djokovic was put under intense pressure by his athletic opponent, making 20 unforced errors and facing six break points.

Djokovic broke Prizmic at the start but the teenager kept ripping huge forehands and stayed with the world number one in several rallies to put the match back on serve before breaking again for a 3-2 lead after a 15-minute battle of a game.

It had been six years and 28 matches since Djokovic last lost a match at the Australian Open and he was not going to put that record at risk easily.

He regrouped, changed his shirt and won the next four games to take the set, pumping his fist and letting out a huge roar in a tribute to the problems Prizmic had caused him.

More than three hours of playing with one of the best players of all time started to take its toll on Prizmic and Djokovic drove home his advantage to take his 90th win at the Australian Open.

The next challenge to Djokovic’s bid for a record 25th Grand Slam singles title will come from one of two Australians, Alexei Popyrin or Marc Polmans.