Main rival and reigning champion Max Verstappen, who had looked like taking the top slot for Red Bull, had to settle for second after a late problem wrecked his final effort.
Ferrari’s home hero Carlos Sainz secured third place on the grid for Sunday, with George Russell taking the fourth slot for a revived Mercedes team.
Russell’s team mate and seven times world champion Lewis Hamilton qualified sixth, behind Red Bull’s Sergio Perez.
“It was a very, very difficult session…because I did a mistake in the opening and then obviously I only had one lap,” said Leclerc after his fourth pole in six races and second in succession.
He had spun in his first flying lap of the final session and, with Verstappen fastest, was then left with one lap and everything riding on it.
“It went extremely well, I had (some) moments on my lap but at the end I made it stick and I’m very, very happy with pole position,” he said.
Verstappen, who has won the last two races to close the championship gap to 19 points, complained over the radio of a loss of power at the key moment in the final phase.
“I couldn’t do my final run. I had a DRS (drag reduction system that) didn’t open or I just lost power, so it’s a bit of a shame,” said the Dutch driver.
“But I think, overall, to be on the front row for us here, looking at the whole weekend so far it was a good achievement. But, of course, I would have liked to go for that final run.”
Sainz, who has yet to win in Formula One, said everything was still possible.
“Conditions haven’t been the easiest with the heat, with the wind, but today we managed to put in a decent lap which means we can fight tomorrow,” he said. (Reuters)