Lando Norris capitalised on a late change to slicks to claim his first Formula 1 pole position at the Russian Grand Prix.
As heavy rain earlier in the day eased off, qualifying was able to go ahead as planned in Sochi, and it appeared Lewis Hamilton was easing to another P1.
But as drivers gambled on dry tyres for the final runs in Q3, it all changed as Norris continued McLaren's momentum from their win at Monza by scoring their first pole since Brazil 2012.
Review
Q1
Already starting at the back of the grid for a new engine, Max Verstappen only completed two laps before returning to the garage in his Red Bull.
At the front, Hamilton set the pace ahead of teammate Bottas, as the circuit offered good grip despite the amount of rainfall beforehand.
Despite the drying conditions, lap times didn't really improve late on as Kimi Raikkonen would be the first driver eliminated in 16th.
Mick Schumacher impressed in 17th for Haas, Antonio Giovinazzi spun en route to 18th and Nikita Mazepin was 2.7s slower than the rest in P19.
Q2
With the track not yet ready for slicks, all drivers remained on intermediates as Hamilton continued to set the pace.
In the battle to make Q3, a last-gasp lap by George Russell saw Sebastian Vettel knocked out by just 0.052s in P11.
Improvements by Carlos Sainz and Daniel Ricciardo meant frustration for Pierre Gasly as a mistake saw him only P12, just ahead of AlphaTauri teammate Yuki Tsunoda.
Nicholas Latifi and Charles Leclerc both didn't set a time due to grid penalties for a new power unit.
Q3
The first run saw Hamilton a massive six-tenths clear as Norris pipped Bottas into second by just 0.004s.
Russell though would be the first to see the track was just about dry enough for slicks and pitted in the Williams.
The rest followed, but Hamilton would hit the pit wall on the pit entry, damaging his front wing and costing him valuable time as Mercedes prioritised Bottas' switch to dry tyres.
Lewis Hamilton hits the pit lane wall! 😯
— Formula 1 (@F1) September 25, 2021
His front wing is damaged - and he faces a race against time to put in another flying lap #RussianGP #F1 pic.twitter.com/txQInKXk50
On the track, lap times didn't immediately improve as drivers struggled to build temperature, but Sainz would be the first to start setting faster times on his final lap.
He would go fastest by 1.5s over Hamilton's initial benchmark on intermediates, before Norris went another half a second quicker, setting the eventual pole time of 1m41.993s.
After P2 at Spa, Russell secured third on the grid in Sochi, ahead of Hamilton, who struggled for grip and spun into the barrier during his only flying lap on the slicks.
Ricciardo took fifth with Fernando Alonso sixth, while Bottas slipped to seventh as he too struggled when the Mercedes changed to the soft tyres.
Lance Stroll was eighth, ahead of Sergio Perez, who failed to be a factor for Red Bull. Esteban Ocon completed the top 10 for Alpine.
So a sting in the tail for Hamilton and Mercedes, but with Verstappen starting P20 they're still in a good position to capitalise heading into Sunday.
What drama awaits us next in Sochi?
