Leclerc is the first driver in history to claim multiple poles in Azerbaijan, and his top qualifying performance extended his Saturday streak to four pole positions in a row and six overall for the season.
The Monegasque had put together a somewhat scruffy first flying lap for the pole shootout, but there would be no denying him the second time around. A centimetre-perfect run between the barriers put him an unreachable first in the order, his margin settling at 0.282 seconds ahead of Sergio Perez when the flag fell.
“It feels good,” he said. “Obviously all pole positions feel good, but this one I probably did not expect it.
“In the last lap everything came together and I managed to do a good lap, so I’m extremely happy.
“Overall our race pace has done a step up since we brought the upgrade [last month], so tomorrow will be very interesting whether it’ll be the case here too.”
Perez was the lead Red Bull Racing driver, but he was disappointed not to have the benefit of a slipstream down the 2.2-kilometre front straight after a fuel calculation problem had him held in the garage longer than anticipated for his final lap.
The Mexican admitted it probably wouldn’t have been enough to overhaul Leclerc, but after having traded times with him all weekend, the inability to hit back clearly unsettled him.
“It was not an ideal qualifying, because in the end I had a problem with the engine,” he said. “We couldn’t turn it on.
“It meant I was basically on my own, and the tow’s very powerful around here.”
Max Verstappen was similarly disappointed with third, but the championship leader was optimistic he’d have competitive race pace on Sunday.
“Overall we seem to lack maybe a tiny bit over one lap, but clearly normally in the long run our car should be quite good,” he said.
Carlos Sainz will start alongside Verstappen in fourth after having provisional pole at the end of the first laps but being unable to improve late.
George Russell gave Mercedes best-of-the-rest honours in fifth, but the Briton was an enormous 1.3 seconds off the pace and almost an entire second slower than Sainz to fourth.
The ailing German marque was struggling so much that Lewis Hamilton qualified only seventh, with an excellent Pierre Gasly splitting the Silver Arrows in sixth for AlphaTauri.
His teammate, Yuki Tsunoda, was eighth ahead of Sebastian Vettel and Fernando Alonso.
McLaren’s Lando Norris and Daniel Ricciardo will line up 11th and 12th ahead of Esteban Ocon’s Alpine.
Chinese rookie Zhou Guanyu qualified 14th and will start ahead of Alfa Romeo teammate Valtteri Bottas for the first time in his career.
Kevin Magnussen will start 16th on the grid after a frantic two-minute Q1 shootout saw Lance Stroll crash his car and cause a red flag deep in the opening session.
The track was extremely congested at the resumption, and several drivers then had their laps compromised by Fernando Alonso running into the turn 15 escape area, causing yellow flags and forcing those behind him to slow.
Kevin Magnussen was knocked back to 16th as a result, ahead of Thai driver Alex Albon, who was directly behind Alonso and incensed by what he thought was gamesmanship rather than a genuine mistake.
Nicholas Latifi will start 18th ahead of Stroll, while Mick Schumacher will start last after being forced to abandon his final lap.