Sebastian Vettel topped Ferrari's first front-row lock-out in nine years as Ferrari surged ahead of Mercedes in Qualifying for the Russian GP.
Vettel's pole position ahead of team-mate Kimi Raikkonen marked the end of 18 consecutive pole positions for Mercedes in a thrilling session at Sochi.
"The car was phenomenal," said Vettel as he celebrated the 47th pole of his career but only the second in Ferrari red.
Valtteri Bottas was the quickest Mercedes driver with Lewis Hamilton only fourth after an error-strewn display in which both Silver Arrows cars struggled to maintain tyre life through the final sector.
"Hamilton, half a second adrift, really had an awful qualifying by his standards," noted Sky F1's Martin Brundle.
"Every time we get on board with Lewis he's been having a drama - the car will not stick to the road."
The last time Mercedes failed to qualify on the front-row was in 2015 at Singapore. Despite pre-event expectations that the Sochi lay-out would suit their W08 car they have instead so far played second fiddle throughout to Ferrari.
"They have had the upper hand all weekend," conceded Bottas.
The timesheets told a similar tale with the Scuderia on top in every session although it was Raikkonen who looked on course for pole at the start of Q3 when the Finn led from Bottas.
But Vettel then produced a last-gasp lap of 1:33.194 to edge out the Finn by less than a tenth. Hamilton had been the fastest driver through the opening two sectors but then lost a huge chunk of time through the final third after losing tyre performance.
"I just wasn't quick enough today, it was all in the last sector - half a second was in the last sector - so there's some work to do," said Hamilton.
"Ferrari are quickest in qualifying and generally in race trim."
Daniel Ricciardo was fifth for Red Bull as the former world champions, impatiently awaiting the introduction of their B-spec car at next month's Spanish GP, slumped almost two seconds adrift. Underlining how far Red Bull have fallen adrift of Mercedes and Ferrari, Felipe Massa compounded Red Bull's misery by demoting Max Verstappen to seventh.
Nico Hulkenberg also excelled as he took eighth for Renault - in sharp contrast to the struggling Jolyon Palmer who crashed out after missing all of Practice Three.
Sunday's race starts at 1pm with build-up coverage underway from 11.30am on Sky Sports F1.
Russian GP Qualifying
1. Sebastian Vettel, Ferrari, 1:33.194
2. Kimi Raikkonen, Ferrari, +0.059
3. Valtteri Bottas, Mercedes. +0.095
4. Lewis Hamilton, Mercedes, +0.573
5. Daniel Ricciardo, Red Bull, +1.711
6. Felipe Massa, Williams, +1.916
7. Max Verstappen, Red Bull, +1.967
8. Nico Hulkenberg, Renault,+2.091
9. Sergio Perez, Force India, +2.143
10. Esteban Ocon, Force India, +2.236
Qualifying Two
11.Carlos Sainz, Toro Rosso, 1:35.948
12. Lance Stroll, Williams, 1:35.964
13. Daniil Kvyat, Toro Rosso, 1:35.968
14. Kevin Magnussen, Haas, 1:36.017
15. Fernando Alonso, McLaren, 1:36.660
Qualifying Three
16. Jolyon Palmer, Renault, 1:36.462
17. Stoffel Vandoorne, McLaren, 1:37.070
18. Pascal Wehrlein, Sauber, 1:37.332
19. Marcus Ericsson, Sauber, 1:37.507
20. Romain Grosjean, Haas, 1:37.620
Will Ferrari stay ahead of the pack in Sochi? Watch the Russian GP weekend with Sky Sports F1. The race begins at 1pm on Sunday. Check out all the ways to watch live F1 on Sky Sports for subscribers and non-subscribers - including a NOW TV day pass for £6.99!