Lando Norris and Oscar Piastri have both been disqualified from the Las Vegas Grand Prix.
The McLaren drivers have been penalised for excessive skid-block wear.
Post-race checks showed the measured thickness was less than nine millimetres on both cars, which is the minimum thickness required.
Max Verstappen now trails Norris by only 24 points and is level with Piastri.
Norris initially finished runner-up to Max Verstappen in Sin City, but following the ruling, he will not receive any points for the race.
George Russell and Kimi Antonelli now move up to take the second and third positions.
With 58 points still available across the Qatar Grand Prix, which includes a sprint race worth eight points, and the season finale in Abu Dhabi, the potential blow to McLaren could prove costly in the drivers' championship.
Norris and a McLaren team representative visited the stewards at 11.45pm local time on Saturday, more than two hours after the chequered flag fell.
Lando Norris and Oscar Piastri have both been disqualified from the Las Vegas Grand Prix
|GETTY
Max Verstappen now trails Norris by only 24 points and is level with Piastri
|PA
Speaking on the violations, the FIA stewards said: "The rear skids of Car 81 were measured and found to be below the minimum thickness of 9mm specified under Article 3.5.9 of the Technical Regulations. The relevant measurements were RHS Front 8.88mm, RHS Rear 8.93mm.
"The measuring device was a Mitutoyo Micrometre purchased in May 2025, and according to the manufacturer’s specifications, accurate to within 0.001mm.
" The rear skids were re-measured in the presence of the Stewards and the three McLaren representatives, and those measurements confirmed that the skids did not comply with the regulations.
"The relevant measurements were even lower than those measured originally by the Technical Delegate. Accordingly the Stewards determine that a breach of the Technical Regulations have occurred."
LATEST F1 NEWS
Mclaren unsuccessfully argued that mitigating circumstances existed
|GETTY
McLaren argued that mitigating circumstances existed due additional and unexpected porpoising at the event, limited opportunity to test due to the weather on Day 1, and shortened practice sessions.
They also claimed that the degree of the breach was lower than prior breaches of this regulation in 2025.
However, the FIA argued that there was no provision in the regulations or precedent for any penalty other than the usual disqualification.
Stewards noted that it strongly held the view that the breach was unintentional and that there was not a deliberate attempt to circumvent the regulations.
Norris began from pole position but will now walk away from the weekend with no points
|GETTY
The stewards added: "The FIA also noted the various decisions of the FIA International Court of Appeal and the Stewards, which limit the ability to avoid disqualification for technical breaches.
"Notwithstanding the submission by the Team that there was potentially accidental damage that may have led to movement of the floor which could have caused additional wear, the Stewards do not consider this sufficient to mitigate the penalty."
Earlier this season, Lewis Hamilton was disqualified from the Chinese Grand Prix after the rearmost skid on his Ferrari was less than the 9mm minimum thickness required.
Norris began from pole position but will now walk away from the weekend with no points, while Verstappen closes the gap behind him.
Our Standards: The GB News Editorial Charter