Eighth seed Berrettini, who has dropped only one set in the tournament, will be aiming to win his maiden ATP Masters 1000 title against Zverev on Sunday.
In the bearpit atmosphere of Kyrgios's favourite John Cain Arena, US Open champion Thiem dragged himself off the canvas in a thrilling 4-6 4-6 6-3 6-4 6-4 win over the Australian showman to reach the fourth round.
The Austrian third seed was shellshocked for the first two sets, barely able to lay a glove on Kyrgios, who channelled the crowd's energy to produce some electrifying tennis.
Along the way, Kyrgios smashed a racquet, delivered underarm serves, played 'tweener' shots through his own legs, ranted at the umpire and saved two match points.
Nadal is looking to edge ahead of Roger Federer who also has 20 Slam titles to his name, with the injured Swiss not playing in Melbourne. He plans to return to the ATP Tour at Doha next month.
Yet, for once, Djokovic may hear the rumbling of hooves as the likes of Austrian Dominic Thiem and Germany's Alexander Zverev look to storm the fortress.
Djokovic won his eighth Australian Open title last year and finished the COVID-19 pandemic-blighted 2020 season with the top ranking for a sixth year.
After a year of playing in front of mostly empty stadiums due to Covid-19, he is also looking forward to some atmosphere, with up to 30,000 spectators allowed each day at the Australian Open.
Djokovic earlier told reporters he had taken a walk in a park to celebrate his release from the 14 days of quarantine players coming from overseas were obliged to undergo to play in Australia.
Two weeks later the pair met again in the US Open final but this time it was the Japanese who emerged victorious, picking up her third Grand Slam trophy.
I heard he's pretty good on clay. I heard he played all right a few weeks ago in New York.
"He loves it here. Had some amazing results here. Probably playing the best tennis of his life or some of, winning his first Grand Slam a few weeks ago.
Thiem took part in the Belgrade leg of the exhibition event organised by Djokovic where social distancing was minimal and matches were played in front of thousands of fans.
Thiem, who left for an exhibition tournament in his native France after Belgra