Towards the end of Q1 Alpine driver Gasly was one a flying lap when he encountered a nearly stationary Sainz at the final chicane, as the Spaniard was creating space for himself to embark on a final lap attempt.
The incident forced Gasly off onto the escape road, which meant that the Frenchman stayed 17th and was eliminated, rather than improving his lap time to book a comfortable spot into Q2.
A furious Gasly responded that Sainz should be banned for it at the time and afterwards continued to say the Ferrari man's driving was "unacceptable".
Sainz's defence was that he was impeded himself by AlphaTauri's Yuki Tsunoda, who had overtaken him before the chicane and therefore forced the Ferrari man to start his flying lap later than planned.
After hearing from both drivers the FIA stewards have given Sainz a three-place grid drop for the grand prix, demoting him from eighth to 11th. It pushes Oscar Piastri up to eighth, Alex Albon into ninth and Sainz's team-mate Charles Leclerc into 10th.
In their verdict the stewards wrote the following:
"The Stewards heard from the driver of Car 55 (Carlos Sainz), the driver of Car 10 (Pierre Gasly), team representatives and reviewed positioning/marshalling system data, video, timing, and in-car video evidence.
Source: Autosport