Under-par Djokovic takes first step towards Grand Slam history

World number one Djokovic, who is gunning for an 11th Australian Open title to pull clear of Margaret Court on the all-time list of majors, won 6-2, 6-7 (5/7), 6-3, 6-4.

The Serbian, with 24 Slams under his belt, is already the most decorated player in the men's game -- two clear of the injured Rafael Nadal and four ahead of the retired Roger Federer.

The 36-year-old - now boasting a 29-match winning run in Melbourne - was expected to breeze through against Croatia's Prizmic, who is half his age.

But after coasting to the first set he was given a searching examination by the youngster, who leveled the match in a tie-break.

The Croatian qualifier threatened to pull away in the third set but the veteran rallied from 3-2 down, reeling off the next eight games to seize control and he was able to snuff out another late fightback.

"He deserved every applause, every credit that he got tonight," Djokovic after Prizmic left the court to a standing ovation from the Melbourne crowd.

"He's an amazing player, so mature for his age and he handled himself on the court incredibly well. This is his moment, honestly. It could easily have been his match as well."

Djokovic will play either Marc Polmans or Alexei Popyrin, both Australians, in the second round but will be keen to iron out the kinks after an uncharacteristically sloppy display, which included 49 unforced errors.

Women's second seed Sabalenka took to the court after 11:30 pm, determined to wrap things up quickly and she demolished German qualifier Ella Seidel.

The Belarusian world number two, clad in striking red on the blue court, raced through the first set 6-0 in just 22 minutes.

She was denied a rare "double-bagel" but made no mistake on her own serve to seal victory in 53 minutes.

"Super happy to be back in Melbourne -- I have incredible memories from here," said the 25-year-old.

"Hopefully I can stay here till the very last day."

Rublev scare

Men's fifth seed Andrey Rublev was earlier given an almighty scare when he was two sets up and cruising against Brazil's Thiago Seyboth Wild.

His 78th-ranked opponent refused to lie down and breaks in the third and fourth sets set up a tantalising decider against the two-time quarter-finalist.

Rublev failed to convert four match points on Seyboth Wild’s serve at 5-6 in the fifth set but he regained his composure in the decisive tie-break, rallying from 2-5 to triumph on his fifth match point after three hours and 42 minutes.

The Russian collapsed to the ground before letting out a guttural roar, admitting he relaxed in the deciding tie-break, believing he was heading out of the tournament.

"When I was losing 4-1, mentally I gave up and maybe that's what helped me in the end," he said. "I felt it's not my day but then I hit some good serves and good returns."

Former champion Caroline Wozniacki progressed when Polish 20th seed Magda Linette retired injured when trailing 6-2, 2-0.

Wozniacki, who won the title in Melbourne in 2018, came out of retirement last year following the birth of two children.

The 33-year-old former world number one said she believed she can triumph again.

"I feel at home here," she said. "The court brings back amazing memories."

Men's fourth seed Jannik Sinner overcame Botic van de Zandschulp 6-4, 7-5, 6-3 while there were wins for seeded US pair Taylor Fritz and Frances Tiafoe.

It was tougher for former French Open champion and ninth seed Barbora Krejcikova, who came from behind to see off Japanese wildcard Mai Hontama 2-6, 6-4, 6-3.

Injured former top-10 star Matteo Berrettini pulled out of the tournament on the eve of a blockbuster first-round clash with Tsitsipas, who will now face Belgian lucky loser Zizou Bergs.