Kevin Magnussen took full advantage of dramatically changing wet conditions to secure a sensational maiden pole position on his 100th Formula One appearance for the Haas team in Friday's qualifying for this weekend's Sao Paulo Grand Prix.
As heavy rain descended on the Interlagos circuit, the final Q3 session ended in euphoric uproar with the popular and modest 30-year-old Dane sitting in his car celebrating while the clock ran down.
He became the first Danish pole-sitter and the first to achieve the feat for the Haas tea in his 140th Grand Prix and his team's 143rd.
Magnussen clocked a best lap in one minute and 11.674 seconds before a final rainstorm wreaked havoc during which Mercedes' George Russell crashed out and was left in a gravel trap.
He also became the fourth driver to claim a maiden pole position this year, following Carlos Sainz, Sergio Perez and George Russell.
World champion Max Verstappen of Red Bull was second quickest ahead of Russell and McLaren's Lando Norris.
Carlos Sainz of Ferrari was fifth ahead of Esteban Ocon and his Alpine team-mate two-time champion Fernando Alonso, seven-time champion Lewis Hamilton of Mercedes, Segio Perez of Red Bull and Ferrari's Charles Leclerc.
"I don't know what to say," said Magnussen. "The team put me out on the track at exactly the right moment. First out of the pit lane. It is incredible!"
Asked to reveal his plan for Saturday's sprint race, he grinned. "Maximum attack! Let's go for something really funny."
Verstappen and Russell warmly congratulated the Dane who appeared almost bemused by his feat. "It's incredible," said Magnussen.
After a bright, warm morning, qualifying began in damp conditions, following a rainstorm, with heavy clouds overhead and all of the early Q1 runners venturing out on 'intermediate' tyres.
Verstappen, Alonso and Ocon chose to delay their first foray while Hamilton reported 'it is quite slippery'. Leclerc set the early pace before Verstappen joined the fray and, almost instantly, went top by two-tenths.
Alonso then took over before Pierre Gasly of Alpha Tauri switched to 'slicks', a bold move. Initially, he struggled. Hamilton went top before Gasly's gambled paid off as he went fastest, sending everyone in for 'slicks'.
This swept in a rush of increasingly fast laps as Williams' Nicholas Latifi, Norris and then Alex Albon of Williams clocked the quickest lap, leaving Ferrari looking both slow-witted in making a decision for 'slicks' and on-track as Leclerc sought to escape the cut.
These conditions contrived to deliver a thrilling final flurry of action as Hamilton and then Norris seized the initiative ahead of Alonso while, ultimately, it was mostly the usual suspects who were eliminated.
Mick Schumacher was 20th and last for Haas and went out with Latifi, Zhou Guanyu and his Alfa Romeo team-mate Valtteri Bottas and Alpha Tauri's Yuki Tsunoda.
In the threatening conditions, all 15 men in Q2 went out again on slicks.
After their opening salvo of laps, Perez, Russell and Hamilton were in the bottom five as 'spits of rain' were reported, Russell complaining that his 'scrubbed' tyres should be replaced with new rubber to ensure progress to Q3.
Verstappen then went top in 1:11.318 after enjoying a slipstream from Stroll's Aston Martin. "It's definitely getting darker here with a bit of drizzle," said Verstappen.
With six minutes remaining and light rain falling, Hamilton and Russell were among the bottom five, but Mercedes pitted the pair who responded by taking third and fourth places behind Verstappen and Alonso.
Timing was, as so often, critical. Within seconds, the drizzle turned to rain, notably in the second half of the lap, but few slowed - and in a final rush of laps on a dry line, the pack was shuffled again topped by Verstappen and the two Ferraris.
Out went Albon, Gasly, four-time champion Sebastian Vettel of Aston Martin, McLaren's Daniel Ricciardo and Lance Stroll in the second Aston Martin, all missing the top ten shootout.
Ferrari gambled, sending Leclerc out on 'intermediates' in anticipation of heavy rain, but after a fruitless effort, during which he held up Perez, he pitted for slicks - only for Russell to crash with eight minutes remaining. The session was red-flagged to a halt.
The Briton was stuck in a gravel trap, condemning Leclerc to return to Ferrari muttering profanities on team radio as, finally, heavy rain descended.
All this left Magnussen on top, ahead of Verstappen with Russell third - as rain and a glorious finale to a crazy session beckoned. The Dane, in his 100 th race for Haas, was set to be the fourth new pole sitter of the year after Sainz, Perez and Russell.