Piastri openly criticised Norris's aggressive driving and McLaren's decision not to intervene after the incident, which stewards noted but did not investigate.
George Russell secured victory at the Marina Bay Street Circuit, with Max Verstappen finishing second, followed by Norris in third and Piastri in fourth place.
Despite the internal team tension, McLaren clinched the constructors’ championship for the second consecutive year at the event.
The incident presents a management challenge for McLaren to address the growing rivalry between their two drivers ahead of upcoming races.