Rapidly changing conditions in the final part of the Shootout saw Piastri emerge as a chance for pole, holding it as the chequered flag waved.
However, it wasn’t to be with Verstappen inching him out by just 0.011s.
The session began following a 35-minute delay for rain, which for a time was heavy enough to raise concerns the Shootout may not take place at all.
However, as it had done for Qualifying on Friday, conditions lifted, and intermediate tyres were the best option by the time cars headed out.
The delay was necessary, with blowers and sweepers out on track to clear some of the water that had been deposited.
Still, the spray was significant, and visibility when running behind another car was limited.
The first time of the session was recorded by Hamilton, a 2:02.297s from the Mercedes driver.
It was a confidence game with big gaps between the times set by the early runners.
George Russell was more than 2.5s slower than his team-mate while Valtteri Bottas slotted into second for a time.
There was also a degree of track evolution involved as the rain clouds gave out to sunshine, helping dry the circuit.
Oscar Piastri made the most of them to shoot to the top of the totem, his 2:01.311s holding provisional pole before Verstappen crossed the line with another sledgehammer lap.
The Dutchman was 0.9s quicker at the time – that closed but even still remained 0.7s faster.
It was critical to be on track in the improving conditions.
Running a high-risk strategy, neither Haas driver had set a time inside the final two minutes of the session.
Moreover, they’d both pitted with three minutes remaining, a racing stop to bolt on new intermediate tyres.
Both Nico Hulkenberg and Kevin Magnussen had recorded five laps apiece, though they had not set a time.
As the chequered flag waved to end Qualifying 1, the order was far from settled with much of the field still out on laps.
The order changed dramatically; Alex Albon climbed to second and Logan Sargeant to sixth (demoted to seventh with his Williams team-mate crossed the line).
That saw Russell scrape through after a mistake under braking into Les Combes while Hulkkenberg abandoned his lap and ended the session without a time.
As a result, he’ll start 20th in the F1 Sprint, with Zhou Guanyu in 19th, then Kevin Magnussen, Valtteri Bottas, and Yuki Tsunoda.
By the time the second phase of the session began, a dry line was emerging ins some areas.
There were train tracks through Eau Rouge and Raidillon and a clear line through Blanchimont.
The field had headed out in intermediates, though with the circuit coated in sunshine it was only a matter of time before the switch to slicks took place.
Complicating the issue were areas like the final chicane, which were dry on approach but still wet on apex. Les Combes was similar, though the run to Rivage was dry.
Again, being on the track at the end would be critical.
Stroll was the first to brave the slicks, taking a set of medium tyres in the dying stages of Qualifying 2.
He was slow through the first split before skating on at the left-hander following Beau Rivage to draw the red flag.
With 30 seconds remaining, the session was not resumed, and the fate of the field was set.
That saw Ricciardo eliminated, along with Albon, Sargeant, Stroll, and his Aston Martin team-mate, Fernando Alonso – the latter four having not set a lap time.
Conditions only continued to improve, and Qualifying 3 began with all 10 runners venturing out on soft slick tyres.
Damp patches remained, especially off-line, ready to punish those who overstepped.
With reduced session times in the Shootout, there was only time for a fast-slow-fast approach.
That left Hamilton on provisional pole from Verstappen after the initial runs, with Norris third and then Leclerc.
Fastest through the middle sector, Sergio Perez encountered a swarm of five cars at the final chicane, compromising the end to his lap.
He still went fastest, 0.895s clear of what Hamilton had managed earlier.
However, others were still on flying laps, including Pierre Gasly, who also went fastest through the middle sector.
The track was ramping up, the Alpine driver usurping Perez by 0.6s to underscore that.
Times tumbled, and for a time it looked as though Piastri would snag pole.
The Australian shot to the top of the totem as the chequered flag waved, only for Verstappen to better him by 0.011s.
The Red Bull driver wills tart from the F1 Sprint pole, joined by the McLaren youngster, with Sainz and Leclerc making for an all-Ferrari second row.
