Norris was on his final flying lap and set to comfortably progress to Q2 when he encountered a slow-moving Esteban Ocon well off the race line through the flat-out turn 18-19 kink leading onto the front straight.
The marshals at this high-speed part of the circuit declared the slow-moving car a hazard, briefly deploying yellow flags through the turns to caution approaching drivers to slow for a potential hazard.
The timing couldn’t have been worse for Norris, who was forced to lift off the throttle to obey the flags, spoiling his lap without enough time to start another one.
McLaren was frustrated after the session given cars in Ocon’s situation are normally covered with white flags, which notify other drivers of a slow-moving car but do not require them to slow.
White flags had been used for Ocon’s car up until that point of the lap, a blind corner combination through which drivers have reportedly asked for more vigilant marshalling owing to its speed.
The result was a blow to Norris’s title ambitions, with the Briton needing to outscore leader Max Verstappen by just under eight points per round to keep his championship hopes alive.
It will have stung particularly keenly given teammate Oscar Piastri put his car on the front row alongside the untouchable Leclerc.
Leclerc, taking his fourth successive pole in Baku, has always performed strongly in Azerbaijan, and he said he knew from his first laps in FP1 on Friday that he would be in the mix this weekend.
“The car felt really good since FP1 and, honestly, we barely changed the car from FP1 to now,” he said. “Straightaway I felt happy and the balance remained really good.
“We had to counter a little bit the track evolution because there was a lot of track evolution, but the feeling was there straightaway.”
Piastri expected a tough battle for victory, declaring that whoever won the first corner would likely have the upper hand for the entire afternoon.
“I think following around here’s going to be really tough,” he said. “Hopefully I can get some clear air. That’d be good. I think our race pace is good, but Ferrari’s certainly not slow.”
Carlos Sainz completed the top three for Ferrari, putting him on the grippier side of the grid from where he was optimistic he could put himself in victory contention.
“To be P3 is a good position for tomorrow, as also my race pace yesterday seemed strong, so all to play for,” he said.
Sergio Pérez looked rejuvenated around his most successful circuit, the two-time Baku winner qualified fourth and 0.448s off the pace. With Verstappen lumbering to sixth, it was the first time since last May’s Miami Grand Prix that Pérez has outqualified the Dutchman.
Sandwiched between the two Red Bull Racing drivers qualified George Russell, with Mercedes teammate Lewis Hamilton in seventh ahead of Fernando Alonso.
Williams got both cars into Q3 for the first time this year, with second-race rookie Franco Colapinto becoming the first driver to outqualify Thai teammate Alex Albon since the 2022 British Grand Prix, with the Argentine set to start ninth ahead of Albon 10th after failing to start his final lap when his team accidentally sent him out onto the track with a cooling fan still attached to his car.
Oliver Bearman, substituting the banned Kevin Magnussen, was superb in his first race for Haas, qualifying 11th and three places ahead of teammate Nico Hülkenberg in 14th, sandwiching Yuki Tsunoda and Pierre Gasly.
Lance Stroll will launch from 15th ahead of Daniel Ricciardo, the knocked-out Norris, Valtteri Bottas, Esteban Ocon and Zhou Guanyu, who was demoted from 19th to last with an engine penalty.