Roger Federer continued to bring the drama to Melbourne Park with an extraordinary comeback to beat Tennys Sandgren in the quarter-finals.
The third seed saved seven match points to move through to a 50th meeting with Novak Djokovic – who easily dismissed Milos Raonic – in the last four on Thursday.
Ashleigh Barty is two victories away from becoming the first home winner of the ladies' title in 42 years after prevailing in her quarter-final match with Petra Kvitova. She next faces first-time semi-finalist Sofia Kenin.
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Kyrgios a big draw
Nick Kyrgios' new-found good standing in his home country had Australians glued to their TVs on Monday night when he took on Rafael Nadal. Channel Nine reported that a peak of more than 3.3 million people – 13 per cent of the population – tuned in to see the Spaniard prevail in an exciting encounter.
Jabeur attracting attention
Ons Jabeur's run made her the first Arab woman to reach the quarter-finals of a grand slam in singles, and the achievement has certainly not gone unnoticed in her home country.
The 25-year-old, who lost to Kenin, said: "My phone is still going crazy right now. I actually talked to the president of Tunisia. He called me. He wished me good luck. That was really nice of him. Everyone is crazy."
Fallen seeds
Women: Petra Kvitova (7)
Men: Milos Raonic (32)
Who's up next?
After his enthralling clash with Kyrgios, Nadal returns to Rod Laver Arena to take on in-form fifth seed Dominic Thiem in the quarter-finals on Wednesday.
The winner of that match will face either 2014 champion Stan Wawrinka or seventh seed Alexander Zverev, the only man yet to drop a set, in the last four.
Wimbledon champion Simona Halep continues her bid for a third grand slam title against Estonia's Anett Kontaveit while Garbine Muguruza meets Anastasia Pavlyuchenkova.