Lewis Hamilton continued where he left off on Friday, topping the final practice session from Melbourne.
The Briton's fastest lap, set on the soft tyre, read 1:22.292 which was three-tenths of a second quicker than his fastest time yesterday.
The Ferrari duo of Sebastian Vettel and Charles Leclerc were second and third respectively, with Vettel two and a half tenths behind rival Hamilton.
After Friday running, Vettel claimed that Mercedes was in a league of its own after blitzing the field, but it now appears the Scuderia outfit has closed the gap overnight.
Valtteri Bottas in the second Mercedes made a mistake on his qualifying simulation and ended the session in seventh place, 1.1 seconds down on his pace-setting teammate.
Haas set some promising lap times ahead of the opening qualifying session of the year, with Romain Grosjean and Kevin Magnussen slotting into fourth and fifth place respectively.
Pierre Gasly was sixth, but Red Bull didn't conduct a proper low fuel run throughout the day. His teammate Max Verstappen was ninth, behind Daniil Kvyat but ahead of former partner Daniel Ricciardo, who rounded out the top ten.
There were no major dramas during the session other than Robert Kubica touching the wall on the pit lane entry, losing a small part of his Williams that once again brought up the rear of the field.
George Russell, who was once again the faster of the two Williams, was 1.4 seconds behind Lando Norris, his nearest competitor on the track.
Both Alfa Romeo's ended up outside the top ten, as did the Racing Point pair and the McLaren duo.