Charles Leclerc led Max Verstappen in second practice for the Australian Grand Prix as Ferrari completed a Friday clean sweep.
Championship leader Leclerc set a time of one minute 18.987secs to finish two-tenths ahead of Verstappen.
First practice leader Carlos Sainz finished third quickest ahead of Alpine's Fernando Alonso, who impressed on his qualifying simulation run.
But Mercedes again struggled to make an impression with both George Russell and Lewis Hamilton outside the top 10.
Leclerc was the only driver of the top three to be provided with a clean lap as Verstappen met traffic on one lap and then found himself running wide at turn 13 on his next.
The reigning world champion regrouped to jump ahead of Sainz, who himself found traffic when lapping on soft tyres, preventing a second Ferrari one-two of the day.
Sergio Perez finished behind Alonso in fifth, though unlike his top-four rivals the Mexican set his fastest lap on his first flying attempt.
Esteban Ocon finished sixth to underline Alpine's pace for the weekend ahead of Valtteri Bottas and Lando Norris, who was joined in the top 10 by Daniel Ricciardo.
Mercedes struggles continue
Mercedes finished the session over a second down on leader Leclerc with Russell in 11th and Hamilton 13th.
The issues with getting the W13 into an optimum operating window was clear to see when Hamilton ran wide at turn 12 early on in the session, taking to the gravel trap and dragging debris back onto the track.
Russell experienced no such issue and was able to find three tenths on his team-mate.
But the Silver Arrows will be concerned by the pace of Alpine and Alfa Romeo in particular, with qualifying struggles potentially returning after Hamilton failed to exit Q1 in Saudi Arabia.
Aston Martin endure difficult session
Aston Martin endured a difficult session with data logging limited to only Lance Stroll's car.
The Canadian escaped punishment for an alleged impeding incident in the first session but has booked himself another date with the FIA race stewards for a similar incident with Sainz at turn 13.
Stroll then triggered the only red flag of the session when debris fell from his car at turn 12 as he ran wide and over the kerb.
On the other side of the garage, Sebastian Vettel's mechanical failure in FP1 forced the German to miss the entirety of the second session with the team unable to change his power unit in time to hit the track.
Australian Grand Prix second practice times
1. Charles Leclerc [Ferrari] 1:18.978s
2. Max Verstappen [Red Bull] 1.19.223
3. Carlos Sainz [Ferrari] 1.19.376
4. Fernando Alonso [Alpine] 1:19.537
5. Sergio Perez [Red Bull] 1:19.658
6. Esteban Ocon [Alpine] 1:19.842
7. Valtteri Bottas [Alfa Romeo] 1:20.055
8. Lando Norris [McLaren] 1:20.100
9. Pierre Gasly [AlphaTauri] 1:20.142
10. Daniel Ricciardo [McLaren] 1:20.203
11. George Russell [Mercedes] 1:20.212
12. Yuki Tsunoda [AlphaTauri] 1:20.424
13. Lewis Hamilton [Mercedes] 1:20.521
14. Lance Stroll [Aston Martin] 1:20.611
15. Guanyu Zhou [Alfa Romeo] 1:21.063
16. Kevin Magnussen [Haas] 1:21.191
17. Alex Albon [Williams] 1:21.912
18. Mick Schumacher [Haas] 1:21.974
19. Nicholas Latifi [Williams] 1:22.307
20. Sebastian Vettel [Aston Martin] NO TIME