The flashpoint came on lap eight of the 44-lap Formula 1 race as the McLaren driver activated overtake mode and used substantial battery deployment to challenge Leclerc on the approach to Les Combes.
Having pulled alongside in a manoeuvre completed by several other drivers during the race, Piastri felt Leclerc moved across, leaving insufficient room and forcing him onto the kerb before the pair made contact.
“Although Car 81 had achieved some overlap with Car 16, its front axle was not ahead of the front axle of Car 16. From the stewards’ perspective, there was no realistic possibility of Car 81 completing the overtake from that position,” the stewards stated.
The impact damaged Piastri’s McLaren, requiring a replacement front nose at his pit stop. Once repaired, his pace recovered.
Although Piastri stopped short of saying Leclerc definitely merited a penalty, he argued the stewards should have at least issued a black-and-white warning flag, typically a driver’s final caution before a penalty.
“From where I was sat, I was on the white line and got squeezed. I think we were both very lucky not to have a bigger crash, because we touched wheels at the start of the braking zone, basically,” said Piastri.
“I don’t really know where I was supposed to go. So, the fact that it was no [further action]… I’m not saying it needed to be a penalty necessarily, but at least a black-and-white flag or something like that.
“If we think that that’s fine, it’s one thing having touches like that, but even just the incentive of knowing that you can leave everyone the absolute bare minimum space, and get away with it, it’s not the nicest place to go.”
He added: “I mean, the first stint, I think the damage was a big player, because I lost a decent bit of downforce, but it impacted the balance of the car a fair bit. So I was struggling a lot from then on until we could change the front wing and compensate a little bit.
“I think the second stint looked a fair bit better. Just once Lewis got ahead, the car was tricky to drive in clean air. And once Lewis got ahead and I was in the heavy following, it was incredibly tough again, and once I kind of dropped back a second and a half or 2 seconds, the pace stabilised again.
“But then even so, the car was still damaged, so I think that was definitely a factor. But I agree that we looked very competitive at the start of the stints and maybe not quite as good at the end.”
Earlier, Lewis Hamilton had been handed a five-second penalty for first-lap contact with George Russell at the same corner, fuelling expectations Leclerc might face similar punishment. Instead, officials ruled no further action was necessary.