Piastri and Norris both retired from the sprint race as Max Verstappen made up ground in the chase for the world title

Oscar Piastri labelled his first-lap collision with teammate Lando Norris in the United States sprint a "racing incident" as he refuted accusations that he was at fault for the crash which dumped the title rivals out.

Piastri, from third on the grid, attempted to cut back inside Norris at the steep turn one at the Circuit of the Americas, but turned straight into Sauber's Nico Hulkenberg.

The Australian's car was lifted up and bounced into the left rear of Norris' McLaren, with the British drivers' tyre sent careering across the track.

Norris was immediately out, with Piastri limping on briefly before suspension damage also put pay to his involvement.

It was a costly incident for the title rivals and allowed sprint victor Max Verstappen to close within 55 points of Piastri and 33 of Norris.

McLaren decided to impose unspecified "consequences" on Norris after deeming him responsible for banging wheels with Piastri in Singapore a fortnight ago.

That was a minor tap in comparison to the first-lap carnage in Austin, with many pundits - including former world champion Jenson Button - apportioning blame on Piastri.

"I think for me it's a racing incident. I was a long way away from the apex and I think the cars behind were going in pretty deep to the corner," Piastri said.

"Could I have done something a bit different? Maybe yes, but that different thing would have been to potentially let two or three cars go by.

"I think a racing incident is fair."

McLaren chief executive Zak Brown was initially robust in defence of his driver on the pit wall, telling Sky Sports: "That's some amateur-hour driving by some drivers up there at the front."

He later withdrew his assessment that Hulkenberg was at fault, but did not specify who he felt was.

McLaren's decision to involve themselves in the title fight by sanctioning Norris after Singapore, for a first-lap manoeuvre which was deemed legal by the FIA, will prompt questions over what they decide to do after this latest collision.

Norris believes it will also be looked at after the weekend.

"I think it will be reviewed just to understand a few more things. Yeah, but apart from that, nothing I can do. I just have to crack on and do my own thing.

"As a team we don't want these things to happen."

Piastri endured a difficult day in Austin and could only manage sixth on the grid in qualifying for Sunday's 56-lap race.

Verstappen, who has also finished ahead of the McLaren pair at each of the last three races, again claimed pole to further insert himself into the title picture with 166 points still to fight for.

Norris was three tenths behind in second but will be heartened to have Charles Leclerc, George Russell and Lewis Hamilton between him and title rival Piastri on the grid as he seeks to cut the 22-point gap in the standings.

Oscar Piastri claims costly crash with teammate Lando Norris was a 'racing incident'