Aston Martin suffered double disaster in the final practice session for the Australian Grand Prix as both Sebastian Vettel and Lance Stroll crashed out at Melbourne's Albert Park.
Both caused red flags, with the second following Stroll's incident bringing an early end to the running by five minutes, with 16 lost overall given the recovery that was required for Vettel's smashed AMR22.
It meant that McLaren's Lando Norris finished top of the timesheet with a lap of one minute 19.117secs, finishing 0.132s ahead of Friday pacesetter Charles Leclerc in his Ferrari.
Setting the scene for a potentially thrilling qualifying session, there were four different constructors occupying the top-four places as Red Bull's Sergio Perez was third quickest ahead of Fernando Alonso in his Alpine.
Norris' lap was 0.139s slower than Leclerc's leading time from Friday as shortly before the start of FP3 the FIA announced it had removed one of the four DRS zones on the grounds of safety, notably the most powerful on the track between turns eight and nine.
Arguably, Norris' time may have been bettered given the time remaining before Stroll went off at turn 11, burying his front-left wheel into a barrier.
It completed a session to forget for Aston Martin given Vettel sparked the first red flag 15 minutes in.
Emerging out of the turn nine left-hander, Vettel lost the rear of his car on approach into 10, smashing the left-hand side into a tyre barrier.
After sustaining a power unit issue with 15 minutes remaining of FP1 that forced a change and the four-time F1 champion unable to make it on track for FP2, it means Vettel heads into qualifying with just 65 minutes of running under his belt this year.
The German driver sat out the first two races after contracting the coronavirus, and by his own admission recognised on Friday he would be at a disadvantage going into this weekend, little realising how a PU failure and an error would add to his woes.
Behind the leading quartet, separated by just 0.158s, was Ferrari's Carlos Sainz, with home hero Daniel Ricciardo giving his fans something to cheer as he was sixth quickest, 0.576s behind team-mate Norris.
Reigning champion Max Verstappen, who went for a spin across the grass out of turn 13 at one point that left him bemoaning his car's balance, was left down in seventh, but without a time on the soft tyres.
On his first run on the red-striped rubber, Verstappen's initial lap was aborted after he missed the apex of turn six, resulting in him complaining about a lack of understeer.
On his second attempt, Verstappen went too deep into turn one and again backed out
shortly after which Stroll ended the session. It meant the Red Bull driver's best lap was on the mediums of 1:19.809s.
Driving what appeared to be a ragged W13 at times, Lewis Hamilton and George Russell both went off track, with the former kissing a barrier at one stage moments before Vettel crashed out.
Hamilton at least recovered to offer a semblance of hope he may reach the top 10 in qualifying as he was eighth quickest, 0.779s behind Norris, with Alfa Romeo's Valtteri Bottas and Yuki Tsunoda in his AlphaTauri completing the top 10, with Russell 11th.
Vettel naturally sat at the bottom of the timesheet without a time to his name, with Stroll 19th and last of those that did post a lap, 2.519s off the pace.
Australian Grand Prix final practice results
1. Lando Norris [McLaren] 1:19.117
2. Charles Leclerc [Ferrari] +0.132
3. Sergio Perez [Red Bull] +0.148
4. Fernando Alonso [Alpine] +0.158
5. Carlos Sainz [Ferrari] +0.302
6. Daniel Ricciardo [McLaren] +0.576
7. Max Verstappen [Red Bull] +0.692
8. Lewis Hamilton [Mercedes] +0.779
9. Valtteri Bottas [Alfa Romeo] +0.891
10. Yuki Tsunoda [AlphaTauri] +0.954
11. George Russell [Mercedes] +0.979
12. Pierre Gasly [AlphaTauri] +1.016
13. Esteban Ocon [Alpine] +1.088
14. Mick Schumacher [Haas] +1.575
15. Zhou Guanyu [Alfa Romeo] +1.719
16. Alex Albon [Williams] +1.841
17. Kevin Magnussen [Haas] +1.908
18. Nicholas Latifi [Williams] +1.933
19. Lance Stroll [Aston Marti]n +2.519
20. Sebastian Vettel [Aston Martin] no time