Valtteri Bottas strengthened his claims as a serious F1 title contender by taking a resounding pole position ahead of Mercedes team-mate Lewis Hamilton for the Spanish GP.
The Finn's third pole position in a row was his most impressive yet with his advantage over world champion Hamilton a full six tenths of a second.
"Big statement from Bottas after his error in practice three and a stunning lap time," said Sky F1's Martin Brundle of the world championship leader.
"That must be one of Bottas' best-ever laps. He's in a whole different bracket there to his team-mate."
Mercedes' advantage at the Circuit de Catalunya this weekend is such that, although Hamilton trailed his team-mate by an unusually large margin, he still starts second on the front row ahead of Ferrari's Sebastian Vettel.
"Ultimately it just wasn't a good enough job," admitted Hamilton.
Ferrari's latest round of upgrades have not delivered a breakthrough in performance with third-fastest Vettel 0.8s off the pace and Charles Leclerc falling behind Red Bull's Max Verstappen in fourth and fifth respectively.
Pierre Gasly was sixth in the second Red Bull, ahead of the impressive Haas pair of Romain Grosjean and Kevin Magnussen.
Daniel Ricciardo made the top 10 for Renault, but team-mate Nico Hulkenberg dropped out in Q1 after hitting the barriers early in the session. Ricciardo, however, will start 13th owing to a three-place grid penalty from Baku for reversing into Daniil Kvyat, who qualified ninth here.
McLaren had appeared likely Q3 finishers but Lando Norris (11th) and Carlos Sainz (13th) just missed out, with the latter running wide at the chicane on his final lap.
Spanish GP Qualifying: Top 10
1. Valtteri Bottas, Mercedes
2. Lewis Hamilton, Mercedes
3. Sebastian Vettel, Ferrari
4. Max Verstappen, Red Bull
5. Charles Leclerc, Ferrari
6. Pierre Gasly, Red Bull
7. Romain Grosjean, Haas
8. Kevin Magnussen, Haas
9. Daniil Kvyat, Toro Rosso
10. Daniel Ricciardo, Red Bull
Bottas makes the difference amid Merc domination
Bottas had set the Friday pace but had appeared in danger of losing momentum when he spun and beached his Mercedes in Saturday morning's final practice session.
However, in keeping with his consistent and impressive form since the start of the season, the Finn immediately regained momentum and had already outpaced Hamilton by a tenth in Q2 before upping the ante in the decisive pole shootout.
"I really enjoyed it," a beaming Bottas told Sky F1's Jenson Button. "I enjoy the adrenaline rush you get from those laps. Practice Three was difficult with the spin but I forgot about that and moved on."
Hamilton, meanwhile, had to stomach not only his third qualifying defeat in a row to Bottas, but the largest gap between first and second on the grid since Spa last August. A battery that wasn't full charged and traffic at the start of Q3 hindered him, but the world champion offered no excuses.
"Valtteri did a fantastic job, he's been quick all weekend," Hamilton said. "On my side I didn't put the lap together. The last laps, in Q3 particularly, just weren't strong. Ultimately it just wasn't a good enough job.
"It's great for the team to have this one-two so we'll try and convert that, but if I can reverse it I'll be happy."
What happened to Ferrari?
There was more Saturday night soul-searching for Ferrari as hopes that their upgraded car and engine would move them closer to runaway championship runners Mercedes gave way to a Q3 deficit of eight tenths of a second.
With the SF90 consistently losing pace in Barcelona's twisty final sector, Vettel conceded: "It seems to be more than an Achilles' heel at the moment. They were both very happy with the car, the last sector for us was a bit more tricky. I think we got everything out of the car. I'm happy, but not happy.
"The car doesn't feel bad but obviously we are not quick enough."
Leclerc was even more frustrated after losing out on a place on the second row to Verstappen, with the Ferrari youngster again not hooking up his best laps when it mattered in Q3. Leclerc completed only one run in the final phase after needing a second attempt to make the top 10 in Q2.
When's the race?
The Spanish GP starts at 2.10pm on Sunday, live on Sky F1. Build-up coverage begins at 12.30pm and will be available through Race Control on the Sky Sports App as well as on Sky Go and the Sky F1 channel.
Watch the Spanish GP live only on Sky Sports F1 this weekend. Sunday's race starts at 2.10pm. Sky Sports is the home of live and exclusive F1. Find out more here to watch the 2019 season live