Red Bull's Max Verstappen took his first Monaco Grand Prix pole position on Saturday with a breathtaking final qualifying lap to deny Aston Martin's Fernando Alonso the crucial top slot.
Alonso, 41, will start alongside on a front row of double Formula One world champions at a circuit where overtaking is extremely difficult and the Saturday session often decides Sunday's outcome.
Ferrari's home hero Charles Leclerc, who had been hoping for his third Monaco pole in a row, had to settle for third while Verstappen's team mate and closest title rival Sergio Perez crashed and will start last.
"Oh my God I hit the wall two times," gasped Verstappen over the radio after crossing the line in the dying seconds with a best time of one minute 11.365 seconds to beat Alonso by a mere 0.084 seconds.
Alonso, the oldest driver on the grid whose last win was a decade ago, had looked set to seize pole with a blistering effort.
But Verstappen delivered when it mattered with a barnstorming final sector.
"We needed to pull that out the bag, but very lovely," he said as team boss Christian Horner declared it a "mighty" effort.
The pole was the 23rd of Verstappen's career.
French driver Esteban Ocon qualified fourth for Renault-owned Alpine with Spaniard Carlos Sainz fifth for Ferrari and seven times world champion Lewis Hamilton sixth in a revamped Mercedes.
Alpine's Pierre Gasly lines up seventh, with Mercedes' George Russell eighth, AlphaTauri's Yuki Tsunoda ninth and McLaren's Lando Norris 10th.
Last year's winner Perez, 14 points behind Verstappen after five races, will start last after crashing at the Sainte Devote first corner in the opening session.
The Mexican also crashed on the approach to the tunnel in the final phase of qualifying last year but started third, and ahead of Verstappen.
This time the damaged Red Bull car was lifted off the track by crane, with the session re-starting and Perez's hopes in tatters.
Monaco was a race he had high hopes of winning again, with most of his previous victories secured on street circuits, but that dream has surely disappeared now.
Both the Haas cars of Kevin Magnussen (17th) and Nico Hulkenberg (18th) failed to make it through the first session in what will be the team's 150th race.
Aston Martin's Lance Stroll also had a disappointing qualifying compared with his team mate, only 14th on the grid and behind the Williams of Alex Albon in 13th.