Valtteri Bottas delivered a statement of championship intent by blowing away Lewis Hamilton to secure pole position for the Spanish Grand Prix.
Bottas, who heads Hamilton in the title race by one point, finished a staggering 0.634 seconds clear of his Mercedes team-mate.
It marked Bottas' third straight pole. Ferrari driver Sebastian Vettel will start from third place — he finished almost nine tenths down on Bottas.
Red Bull driver Max Verstappen managed to split the Ferraris. He lines up in fourth ahead of Charles Leclerc.
Bottas might have considered himself fortunate to hang on to his seat at Mercedes following an underwhelming campaign last year in which he failed to win a single race.
But the Finn will be delighted with his start to the season, sharing two victories apiece with Hamilton, and securing yet another pole here.
Hamilton has not been at his best this weekend, and the world champion made an uncharacteristic mistake on his opening timed lap to finish well behind his team-mate.
“Valtteri has been quick all weekend and I just didn’t put the laps together,” said Hamilton. “It just wasn’t a good enough job.
“I will be giving it everything tomorrow. We will try to convert this into a one-two finish and if I can reverse it I will be happy.”
Bottas added: “The season has started well and the way I hope for. I feel better and better in the car.”
Vettel had hoped the Barcelona track would be the venue for his championship fightback.
But the German, already 35 points adrift in the title race, could find no answer for the speed of the Mercedes cars. Indeed, it is looking more and more likely that Bottas could provide the biggest threat to Hamilton’s quest for a sixth world crown.
There were gloomy faces in the Renault garage as Nico Hulkenberg fell at the first hurdle of qualifying. Hulkenberg finished seventh in the championship last year, but his French team are struggling this term.
Daniel Ricciardo, who turned his back on Red Bull to join Renault, did well to get his car into the top 10, but the Australian serves a three-place grid drop after he reversed into Daniil Kvyat at the last race. He will be 13th on the grid.
Ricciardo's penalty promoted Lando Norris to 10th. The Briton, who is steadily impressing in his maiden season, finished two spots ahead of Carlos Sainz in the sister McLaren.
British rookie George Russell finished 1.2 sec ahead of his Williams team-mate Robert Kubica, out-qualifying the Pole for a fifth time in as many races.
The 21-year-old, however, will be demoted to the back of the field, penalised for taking on a new gearbox after he crashed out of final practice.
