Grosjean found himself inside the top five after Haas opted not to pit under a safety car that saw most drivers take a fresh set of tyres.
The Frenchman, on his medium tyres, was issued a black and white flag after he moved more than once along the straight while attempting to keep Carlos Sainz behind.
Grosjean affirmed that he had left Sainz enough space and was seen doing similar moves to Ricciardo as they battled, with the latter describing the defence as “sketchy”.
However, a warning has been given to Grosjean for the incident instead of a penalty. The stewards explained;
“Moving under braking when another car is approaching has been identified by the drivers as a very dangerous manoeuvre,” read a stewards statement.
“Grosjean was given a black and white flag by the Race Director for moving under braking with Sainz.
“The stewards reviewed this case with Grosjean and Ricciardo. They also reviewed the video of the incident between them. Grosjean explained that in both cases his moves were before the braking zone, although in the second case, it was closer.
“When it was put to the drivers that these were late moves in relation to the approaching car, or “Movement in Reaction”, and also potentially dangerous, they agreed on this as a general principal.
“Ricciardo agreed that this situation, while close, was manageable by him as the following driver.
“The Stewards issued a Warning, with the admonition that late movement in reaction to drivers following is also considered potentially dangerous and will be scrutinised by the Stewards.”
Grosjean crossed the line last of the finishers, having made his one and only pit stop deep into the race on an alternate strategy.
Bahrain International Circuit - Winter testing