Max Verstappen claimed his 25th Formula 1 pole position in a rain-hit Canadian Grand Prix qualifying session, as a red flag cemented a front-row start for Nico Hulkenberg.
Although a drying line had emerged by the start of Q2, offering drivers to take a chance on running with soft tyres, the conditions had worsened by the start of the final part of qualifying and the rain picked up in intensity.
Armed with intermediate rubber, Verstappen collected a 1m27.059s with his first lap of the session, as Aston Martin's Fernando Alonso got to within 0.25s of the championship leader's opener in their respective opening gambits.
But although rain continued to fall, Verstappen found enough tyre temperature to produce a 1m25.858s, although Alonso had eclipsed the Dutchman's second sector in his follow-up effort.
But the session was red-flagged, as Oscar Piastri took too much throttle on the exit of Turn 7 and backed his car into the wall, breaking the right-rear corner of his McLaren.
Hulkenberg managed to put in a time good enough for second moments before the red flag emerged, but Alonso was unable to complete his lap and had to retreat to the pits.
The session resumed with seven minutes left on the clock, but the continued precipitation dampened any chances that the drivers could improve in the final half of the session.
Token running thereafter confirmed that, with some of the drivers remarking that the session could only be tackled with the full-wet tyre.
Alonso claimed the third-fastest time having been denied another shot to beat Verstappen, and starts on the second row alongside Mercedes' Lewis Hamilton.
George Russell and Esteban Ocon completed the third row, ahead of Lando Norris in seventh.
Carlos Sainz could only manage eighth, but will likely have to visit the stewards having impeded Pierre Gasly in Q1 in a session where the #55 Ferrari seemed to be of constant irritation to other drivers.
Piastri's time prior to his crash was good enough for ninth, as Alex Albon's Q3 effort was chalked off due to a track limits violation.
Albon had been the first to risk the soft tyres at the start of Q2 as a drying line began to appear, and it was a gamble that paid off once the Anglo-Thai driver collected enough tyre temperature.
The Williams driver fired his way to the top of the timing board and, although then eclipsed by Alonso on the intermediate compound, Albon posted a 1m18.725s to book his place into Q3.
This prompted everyone to try slicks, although Charles Leclerc and Sergio Perez discarded their sets of softs without having set a competitive time on them.
The Mexican bolted on intermediates again as rain returned to the circuit, but was mired in the drop zone and was one of the two high-profile eliminations from the session.
Leclerc was one position ahead, having been dumped into the drop zone as Hulkenberg broke into the top 10 on his own soft-tyre lap.
Home hero Lance Stroll recovered from a spectacular spin on the exit of Turn 5 and narrowly missed the wall, but could only set a time good enough for 13th - beating Nordic duo Kevin Magnussen and Valtteri Bottas.
Q1 was red flagged after just three minutes as Zhou Guanyu lost drive and had to park up on the exit of Turn 7, although the Alfa Romeo drive was able to perform a reset to get the car back to the garage.
The drying nature of the circuit in Q1 put the onus on the drivers to show continual improvement, and the session resembled musical chairs as the midfielders battled against the drop zone.
But both Yuki Tsunoda and Gasly encountered a dawdling Sainz at the chicane, and neither made it through into Q2 - Gasly venting his fury over the radio to suggest that the Ferrari driver "should be banned".
Tsunoda missed out on the cut having been 0.016s shy of Hulkenberg in 15th, who felt the Japanese driver had impeded him during the session.
Nyck de Vries could not improve upon 18th on his final lap, as Logan Sargeant joined Zhou on the final row of the grid as the Chinese driver was able to return to the circuit - albeit slightly hamstrung by his earlier issue.