Piastri made contact with Yuki Tsunoda twice during a fraught battle in the second part of the race.
On the second clash the AlphaTauri driver was pitched off the road when he tried to pass on the outside at Turn 1. The FIA investigated the incident, but ultimately took no further action.
A few laps later Piastri was asked to let Norris by so that the British driver could attack the cars ahead in the course of his spectacular drive from 17th to fifth.
Piastri meanwhile had to settle for eighth, crossing the line some 10 seconds behind Norris.
"Yeah, some big moves," he said when asked about the Tsunoda fight. "I think hard racing.
"The one in the end, I'm not really sure what happened for me, I was just braking and then we touched wheels. So nothing really more than that.
"I had some damage at that point. Lando was very quick compared to everyone, I think. So it didn't make any sense to try and battle each other.
Source: Autosport