Leclerc wins US Grand Prix as Norris and Verstappen clash
McLaren's Norris was penalised five seconds for gaining an advantage by leaving the track to pass the series leader and Red Bull's three-time champion on lap 53 of the 56-lap contest and dropped to fourth.
Verstappen has now extended his lead over Norris to 57 points in the drivers' championship with five races left this season.
Leclerc came home 8.562 sec seconds ahead of Sainz with Verstappen third, adrift by 19.412 seconds, leaving Norris fourth ahead of McLaren team-mate Oscar Piastri and George Russell of Mercedes who finished sixth after starting from the pitlane.
Sergio Perez was seventh in the second Red Bull ahead of Nico Hulkenberg of Haas, Liam Lawson of RB and Franco Colapinto of Williams.
For Leclerc, it was a first victory in the United States, his third of the season and the eighth of his career while for Ferrari it was a first one-two in American since 2006.
"It wasn't an easy weekend up to now, I have been struggling with the feeling with the car, but I had confidence in the race," said Leclerc.
"I am really happy with today, a 1-2 for the team, we couldn't have dreamed for better."
Verstappen said: "It was a difficult race for me. I never had the pace to attack and defending was quite difficult with understeer. It was a tough battle and tough to keep him (Norris) behind but it's a great result.
"I have my opinion about his move, but I'll leave it to the stewards. I dont need to say anything here."
Norris made a good initial start from his fourth pole in five races, but left a critical gap on the inside which encouraged Verstappen to attack, forcing them both wide and allowing Leclerc to snatch the lead from fourth on the grid as they came through Turn One.
'Give it back'
Norris fell to fourth as Sainz also passed him on an eventful opening lap that saw Lewis Hamilton rise from 17th to 12th before he went off at Turn 19 on lap three, prompting an early Safety Car intervention.
The Mercedes star had never previously failed to finish in 11 races in Austin.
The race resumed on lap five, Leclerc pulling away to build his lead to three seconds by lap 10 with Verstappen resisting Sainz, who reported possible fuel problems and a loss of power.
Norris stayed fourth ahead of McLaren team-mate Piastri.
By lap 20, as first the pit-stops began, Leclerc was 8.3 seconds clear of Verstappen with Sainz third, 1.3 adrift of the Dutchman. Norris was 3.6 adrift In fourth.
Sainz came in on lap 21 for hards, rejoining sixth. Verstappen stayed out until lap 26 rejoining fifth, Ferrari having executed their undercut. Leclerc then came in on lap 27 for hards, leaving Norris and Piastri leading the way. He was third.
As Norris pulled clear, Piastri frustrated Leclerc until lap 31 when Norris pitted. He rejoined fifth behind Verstappen and ahead of sixth-placed Russell who had not stopped.
A lap later, Piastri pitted and order was restored with the Ferraris, led by Leclerc, in control ahead of Verstappen and both McLarens.
"These tyres aren't good, I can't brake or attack," reported Verstappen.
Russell finally pitted on lap 41, rejoining eighth on mediums for the final stint as Norris closed in on Verstappen and they fought for third and vital points in their title scrap.
The duo battled fiercely for a dozen laps, the champion defending adroitly each time Norris attacked until lap 53 when, pushed wide and off-track, the Briton finally made his move stick to take third.
"He needs to give me it back," complained Verstappen on team radio as they battled on and the stewards studied the move before hitting Norris with a five-second penalty for gaining an advantage.
