Max Verstappen was fastest in final practice for the Bahrain GP as Red Bull unexpectedly out-paced Ferrari and Mercedes.
Lewis Hamilton was a tenth of a second behind the Dutchman in Practice Three with joint-championship leader Sebastian Vettel a further four tenths down - but the Ferrari driver set his quickest time on used supersoft tyres.
Kimi Raikkonen remained in the Ferrari garage until the final minutes while Red Bull's Daniel Ricciardo only completed one timed lap.
Red Bull have struggled to keep pace with the frontrunning Ferrari and Mercedes so far this year but conditions in the desert appear to suit their car far more than those experienced in Australia and China.
But track temperatures are forecast to drop significantly for this evening's qualifying hour when Ferrari and Mercedes will be expected to battle for pole position.
"Mercedes and Ferrari won't have shown their hand until they need to. But it's a good result for Red Bull and they seem to have caught up. Maybe this track suits them but it's encouraging," said Sky F1's Damon Hill.
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A strong cross-wind played havoc with the drivers throughout the session, with Valtteri Bottas and Verstappen among those going off track.
Haas driver Romain Grosjean hit the track barriers, losing his front-wing in the process, after spinning across the circuit.
Grosjean had repeatedly complained about understeer from his car prior to the crash.
Renault's Jolyon Palmer was slowest of all in 20th place, 12 positions behind team-mate Nico Hulkenberg who is enjoying a strong weekend.
Qualifying takes place at 4pm UK time.
Bahrain GP Practice Three timesheet
1. Max Verstappen, Red Bull, 1:32.194
2. Lewis Hamilton, Mercedes, + 0.110
3. Sebastian Vettel, Ferrari, + 0.556
4. Valtteri Bottas, Mercedes, + 0.560
5. Kimi Raikkonen, Ferrari, + 0.591
6. Felipe Massa, Williams, + 0.607
7. Daniel Ricciardo, Red Bull, + 0.615
8. Nico Hulkenberg, Renault, + 0.739
9. Carlos Sainz, Toro Rosso, + 1.410
10. Daniil Kvyat, Toro Rosso, + 1.550
11. Sergio Perez, Force India, + 1.772
12. Fernando Alonso, McLaren-Honda, + 1.728
13. Pascal Wehrlein, Sauber, + 1.753
14. Lance Stroll, Williams, + 1.771
15. Stoffel Vandoorne, McLaren-Honda, + 1.833
16. Esteban Ocon, Force India, + 1.870
17. Kevin Magnussen, Haas, + 2.004
18. Romain Grosjean, Haas, + 2.011
19. Marcus Ericsson, Sauber, + 2.074
20. Jolyon Palmer, Renault,+ 2.223
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