The Australian impressed once more as he progressed to the final phase of the three-part session with a 1:13.059s in Qualifying 2.
Had he repeated that effort in Qualifying 3 it would have seen him seventh fastest, ahead of Esteban Ocon.
However, a mistake in the slippery final sector meant he could do no better than 1:13.682s.
“Was honestly on a decent lap until that point,” he said when asked about the lap by Speedcafe.
“Broke a little bit too late for Turn 10, missed the apex a little bit, and then hit a wet part of the track and it was game over from there.
“Pretty frustrated with myself,” he added.
“In all honesty, it was a good session until then, just messed up when it counted.
“I think we should have had both cars up towards the front, so a shame, but that's where it went wrong.”
While he qualified 10th fastest, Piastri will start ninth following the double penalty for Pierre Gasly, which drops the Frenchman from fourth to 10th.
The Australian is pragmatic heading into qualifying, aware of cars behind him that are out of position.
George Russell and Gasly also have proved rapid over the course of the weekend.
“Obviously I've got Checo right behind me,” Piastri said of his prospects in the race.
“Looking at Max all weekend, they've [Red Bull] been in another league, probably even more so than the rest of the year, I would say.
“So I think he will come through quite quickly.
“Some other cars as well behind… staying in the points won't be easy but at the same time, I think there's some opportunities ahead as well.
“We'll see what we can do.”