The Honda rider started both the sprint race and the main grand prix from pole after surprisingly topping qualifying.
Marquez converted this to a third-place finish in the sprint and was a factor in the podium battle early on.
An aggressive start saw Marquez force both himself and Pramac’s Jorge Martin slightly wide at the third corner on the opening lap as he tried to reclaim the lead having lost out off the line.
Then on the third tour, Marquez misjudged his braking for Turn 3 and made contact with Martin, before slamming into the side of RNF Aprilia’s Oliveira.
The incident took both Marquez and Oliveira out on the spot, while Martin was dropped to 16th before eventually crashing out having recovered to 10th late on.
Marquez will fly to Barcelona for checks on a suspected fracture on his right hand, while Oliveira suffered some bruising – though appears to have escaped without serious injury.
The stewards summoned Marquez after the race and have handed him a double long lap penalty to be served in next weekend’s Argentina GP should he be declared fit to ride.
Speaking after the incident, Oliveira said: “Today was a shame. Obviously, to end my home GP after two laps is not what I was expecting for sure.
“Anyway, I think we can be very proud of the progression we had, coming from a difficult day on Friday, qualifying like we did yesterday, having the podium in hand in the sprint race.
“The start we made today, leading, coming second, I think today was a clear opportunity to score a podium. From the crash I’m still very bruised on my right side.”
Martin has broken a toe in his foot and has injured his ankle in the Marquez incident, with the Pramac rider nothing “it’s not the first time he destroys my race” in reference to their collision in the 2021 British GP.
“I have broken one toe on the foot, and also on my ankle I have something,” said Martin.
“I don’t know what, I will check tomorrow. But it’s a pity because I had the pace to fight for, I don’t know if it was the victory, but we were quite close without that impact.
“After the impact, he moved my handlebars so I was riding in a difficult way. I was quite fast [still], recovering to the group of the fourth position.
“So, I was quite competitive in the middle of the race. It’s not the first time he destroys my race, so maybe in future he manage to avoid me or at least race direction do something because I never destroyed a race for him or injured me. It’s already the second time, so I hope he can improve.”
