Nadal, the world number five and sixth seed, overcame seventh seed Berrettini 6-3, 6-2, 3-6, 6-3 in the semi-finals to ensure he will get the chance to stand alone atop the list of all-time men's singles Grand Slam champions.

Standing between the 35-year-old and a history-making feat will be second seed Daniil Medvedev of Russia, who ousted Greek fourth seed Stefanos Tsitsipas 7-6, 4-6, 6-4, 6-1 in an ill-tempered affair.

The final at the opening Grand Slam of the season takes place on Sunday (January 30).

Nadal is currently locked on 20 titles with world number one Novak Djokovic, with the Serbian unable to defend his Australian Open crown after being deported from the country following the cancellation of his visa, and Swiss maestro Roger Federer, who is not competing in Melbourne as he recovers from knee surgery.

He threatened to turn his semi-final with Berrettini into a non-event as he raced into a two-set lead, before the Italian showed signs of a fightback by taking the third.

But the Spaniard, aiming for just his second Australian Open title, showed his class to wrap up victory in four sets.

"The first two sets were some of the best I've played for a long time," said Nadal.

"Against a difficult opponent, a great opponent, one of the best of the world, I was able to play I think at a very high level for a long time.

"I had to suffer and I had to fight but it means a lot to be in the final again."

Medvedev, aiming for consecutive Grand Slam titles after winning last year's US Open, was locked in a tight battle with Tsitsipas in the first set, which he won on a tie-break.

The Greek hit back in the second, which included Medvedev angrily urging the umpire to give Tsitsipas a violation for alleged unauthorised coaching from his father.

A tight third went the way of the 25-year-old Russian before he blew Tsitsipas away in the fourth to set up a showdown with Nadal.

"I'm going to play against one of the greatest and someone going for the 21st Slam," said Medevdev.

"I guess last time Rafa was watching [the US Open final] and I don't know who he was cheering for, I guess Novak [Djokovic] will be watching in two days time also.

"I'm ready, I know that Rafa is a very strong player and I need to show my best to try and win this match."

The women's singles final between Australian world number one Ashleigh Barty and American Danielle Collins is due to be held tomorrow.