Lando Norris' bid to win the world championship has taken an extraordinary setback after he was disqualified from the Las Vegas Grand Prix.
Norris had finished runner-up to Max Verstappen in Sin City to put him 42 points clear of the Dutchman in the title race with just 58 to play for.
But Norris and team-mate Oscar Piastri were stripped of their respective second and fourth-placed finishes for running illegal cars after the rearmost skids underneath their McLarens were less than the 9mm minimum thickness required.
It means Norris will head to the penultimate round in Qatar - which includes a sprint race - next weekend guarding only a 24-point lead over Verstappen with the season finale to follow in Abu Dhabi on December 7. After Qatar, the final race follows in Abu Dhabi on December 7.
Piastri, who had been cast 30 points adrift at the chequered flag, is now also 24 points back.
The stunning verdict from the stewards arrived at close to 2am local time - more than four hours after the race finished.
On the track in Las Vegas, a mistake by pole-sitter Norris at the opening corner dropped him to third behind Verstappen and Mercedes' George Russell.
A flustered Norris re-joined the circuit and then came within inches of colliding with Verstappen, and in his desperation to avoid a tangle, allowed Russell to draw alongside his compatriot and blast clear.
Piastri was fortunate to avoid damage after he banged wheels with Liam Lawson while Gabriel Bortoleto wiped out Lance Stroll and Lewis Hamilton, who started 20th and last following a nightmare qualifying session, navigated his way through the mess to make up eight places.
Verstappen resisted the early advances from Russell, and was two seconds clear of the Mercedes man, who was the first to pit on lap 17.
That briefly promoted Norris to second only for the championship contender to fall back behind Russell when he stopped for new tyres four laps later.
Verstappen was able to come in for tyres and keep his lead, and then the attention turned to Norris and whether he could clear Russell.
Russell was struggling to keep up with Verstappen and offered little resistance to Norris, who breezed ahead on the Las Vegas Boulevard on lap 34. The Dutchman's lead, though, never came under threat as he crossed the line 20 seconds clear.
Kimi Antonelli finished fourth, but a five-second penalty dropped him behind Piastri. Charles Leclerc started ninth and finished sixth, four places ahead of Hamilton who claimed a single point on another weekend to forget for the seven-time world champion.
