The Briton wasn’t fastest in any of the three sectors but strung together a silky-smooth lap to snatch top spot from Carlos Sainz by just 0.044 seconds, while Charles Leclerc was a further 146s off the pace.
Championship leader Max Verstappen could manage only 10th after a mistake and a power unit problem hampered him in the shootout.
Russell’s maiden pole and Mercedes’s first for the season came as a shock after a gruelling weekend of struggle. The car was way off the pace throughout Friday practice, and in wet practice earlier yesterday it was badly hamstrung by tyre warm-up issues.
“I’m over the moon. Absolutely buzzing,” he said. “The lap time just kept on coming, kept on coming.
“Yesterday was probably the worst Friday of the season. We need to look into it and understand where that came from today.”
But he said his target was regardless to convert his maiden pole into a maiden win.
“At the end of the day there’s no points for qualifying,” he said. “We’re going to be absolutely going for it.”
Carlos Sainz said Mercedes’s pace had thrown a curveball into his race expectations, though the Spaniard was optimistic his Ferrari would still have the pace to snatch victory.
“The Mercedes pace is a bit of an unknown,” he said. “We’ll have to see how the race plays out tomorrow.
“I think we have the pace. Obviously the start and the tyre management will play a key role, like always.”
Charles Leclerc was similarly dispirited and encouraged his team to identify why its dominant Friday pace didn’t translate into a better result yesterday.
“Mostly we are focusing on ourselves,” he said. “Today’s not been a great day.
“I struggled to put a lap together. We’ll look into it.
“We just need to understand what went on with the tyres today and I’m pretty sure we can come back tomorrow.”
Lando Norris qualified fourth and 0.392 seconds off the pace for McLaren, fending off Alpine teammates Esteban Ocon and Fernando Alonso.
Lewis Hamilton qualified out of position in seventh after a DRS failure prevented him from completing his final lap.
Valtteri Bottas qualified eight for Alfa Romeo ahead of Daniel Ricciardo in the second McLaren.
Red Bull Racing had a shocker of an afternoon, with Verstappen and Sergio Perez qualifying 10th and 11th respectively.
Verstappen made a mistake with his first lap in the pole shootout that left him buried in the order, and a power unit problem subsequently cost him a chance to redress his mistake, putting him 10th on the grid.
But Perez suffered more after being eliminated from Q2 in 11th. He had his first lap struck from the classification for exceeding track limits, and traffic then prevented him from improving with his second attempt.
Zhou Guanyu qualified 12th ahead of Kevin Magnussen and Lance Stroll beat Mick Schumacher to 14th and 15th on the grid.
Yuki Tsunoda was knocked out 16th in Q1 ahead of Thai driver Alex Albon, while Sebastian Vettel was eliminated a distraught 18th after having helped repair his car thanks to a late crash in final practice.
Pierre Gasly had his best lap deleted for running wide at turn 5, leaving him 19th, while Nicholas Latifi will start 20th for Williams.