Piastri lost control when he hit the exit kerb of turn four, skidded and slammed into a barrier, damaging his right front wheel, the front wing and nose of the car.
Third in the championship last season, Piastri said he was OK on the team radio and exited the car before a dejected walk back to the pit.
Mercedes' George Russell won the race ahead of teammate Kimi Antonelli, while Piastri's teammate and defending champion Lando Norris finished fifth.
Piastri, who was to have lined up fifth on the grid, said he was blindsided by a surge in torque in his car but also accepted some of the blame for the mishap.
"We had a couple of things going on," he said in the paddock.
"I think the first part I want to stress is that there is certainly a big element of it that was me. Cold tyres, I have used that exit kerb every lap of the weekend, but I didn't have to.
"At the same time, I had about 100kW extra power that I didn't expect, which is not insignificant."
McLaren boss Zak Brown described it as "a disappointing burp" for Piastri at his home race.
"I'm sure he'll be sore about that one for a while, but these race car drivers know how to recover quickly, so definitely not the way you want to get started, but he'll be back."
F1's new engine era has proved a steep learning curve for drivers, with a number struggling with reliability problems and a new way of driving which involves more emphasis on energy deployment and regeneration.
Overall, it was a sobering day for defending constructors champions McLaren, whose cars were well off the pace.
Norris finished more than 50 seconds after Russell and more than 35 seconds after the third and fourth-placed Ferraris.
He said he felt McLaren were also well behind Red Bull, whose four-times world champion Max Verstappen climbed 14 grid places to finish sixth.
"I think it was really quite clear the Red Bull was a lot quicker -- just because Max came from last and almost beat us," Briton Norris told Sky.
"Not the best race in terms of pace, but we struggled with some things on the car at the beginning.
"Today showed a lot more from a car that we're a very long way off and we have a lot of work to do."