McLaren's Oscar Piastri edged Mercedes' George Russell in an ultra-competitive third and final practice for the season-opening Australian Grand Prix on Saturday, with Lewis Hamilton eighth in his Ferrari.
Australia's Piastri, who won two races last year, flew round his home Albert Park circuit on soft tyres in an eye-catching one minute 15.921 seconds.
That was enough to pip the Briton by just 0.039sec.
World champion Max Verstappen was third with Red Bull appearing to have ironed out the grip issues that caused the Dutchman to complain on Friday.
Verstappen, who took pole position in Melbourne last year, is chasing a second win in Australia after his 2023 victory to kickstart his bid for a fifth consecutive world title, a feat achieved only by Michael Schumacher.
But it was a horror session for his Red Bull teammate Liam Lawson, who took over from the axed Sergio Perez.
Lawson failed to post a time after power issues on his first lap sent him back to the garage.
Ferrari's Charles Leclerc was fourth and Mercedes rookie Kimi Antonelli fifth ahead of Williams pair Carlos Sainz and Alex Albon.
Hamilton, a two-time Melbourne winner, finished eighth as he continues to adapt to life at Ferrari with a different car, team and power unit.
RB's Yuki Tsunoda was ninth with Piastri's teammate Lando Norris a disappointing 10th, but just six-tenths of a second separated the top 10.
On a muggy day, with temperatures forecast to reach 35 Celsius (95 Fahrenheit) before a cool, wet change on Sunday, struggling Haas rookie Ollie Bearman was the first out on medium tyres.
It soon turned to disaster, with the Briton skidding into the gravel on his first lap after his wheel touched the grass bringing out the red flag.
Bearman was unable to continue leaving Haas ruing whether they had made a mistake in signing the 19-year-old who had smashed into the barriers in first practice on Friday.
His car was left in such a mess that he could not go out for the second session so has so far managed to complete only 13 laps ahead of qualifying later Saturday.
When the action resumed nine minutes later, his Haas teammate Esteban Ocon put the first time on the board.
But that was quickly toppled by Alpine's Jack Doohan, with Verstappen then Piastri lowering it substantially on soft tyres.
The benchmark kept tumbling and at the halfway point it was Verstappen, Antonelli, Piastri, Leclerc and Norris.
Leclerc and Hamilton clocked flying laps to challenge Verstappen before Russell surged to the top of the timing sheets with 20 minutes left.
Verstappen asserted control again before Piastri became the first to dip under 1min 16sec and could not be caught as he aims to become the first home winner of a Formula One GP in Australia.
Norris and Leclerc topped the Friday practice sessions.
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