Formula 1 championship leader Kimi Antonelli beat Max Verstappen to pole position for the United States Grand Prix as practice pacesetter Ferrari watched its challenge crumble in qualifying.
Antonelli came good as the qualifying hour went on and beat Verstappen by 0.179s in Q3 to clinch his seventh pole position of the season, while Isack Hadjar made it two Red Bulls in the top three.
Antonelli was one of three drivers - alongside Mercedes team-mate George Russell and the McLaren of Oscar Piastri - to go through Q1 on mediums in order to save an extra set of soft tyres for Q3. (Something Red Bull did too by running Verstappen and Hadjar on one set of softs in Q1 and Q2.)
Having been sixth in Q1, Antonelli then ended Q2 just 0.080s off the Ferrari of Charles Leclerc at the top of the Q2 order, and jumped to provisional pole at the start of Q3 with a 1m34.035s.
He had been more than a tenth up on that time through the second sector on his final attempt, but then had a big correction on the exit of the Turn 13 right-hander that wrecked that attempt and appeared to open the door to his rivals.
But the Red Bulls failed to improve their times - both actually had their final, slower efforts scrubbed off for track-limits offences - and with Leclerc finding less than a tenth, that meant Antonelli held on to pole.
Verstappen said in failing to beat Antonelli that, having come through Q1 and Q2 on the same set of tyres, "for whatever reason on both of those sets [in Q3] I didn't have a good balance".
Third for Hadjar marked a drastic turnaround for the second Red Bull driver after struggling throughout practice, as Ferrari's fortunes went the other way.
Leclerc was fastest even as late on as Q2, and replicating that time in the final session would have netted second place, but he ended up a quarter of a second back in fourth as team-mate Lewis Hamilton salvaged fifth by improving on his final lap.
Russell was more than four tenths away from his polesitting team-mate in Q3 and perhaps fortunate to secure sixth on the grid, as Lando Norris had gone ahead of him too at the end of the session but had his lap deleted for track limits, which dropped him to eighth behind McLaren team-mate Oscar Piastri.
Having got both cars through to Q3, Racing Bulls chose not to run Liam Lawson in the final part of qualifying. That allowed Arvid Lindblad, who has a five-place grid penalty to serve on Sunday, to qualify ninth and potentially drop one place less than he otherwise would have done.
Audi's Q2 gamble fails
Audi ran its drivers out of sync with the opposition at the end of Q2 in a bid to get Nico Hulkenberg through with the assistance of a tow from team-mate Gabriel Bortoleto, carrying a hefty grid penalty this weekend for engine component changes.
Bortoleto even reported after the session "I hope he went through with this tow I gave, f*** it was a big one", but in reality Hulkenberg looked a long way behind his team-mate on the back straight.
His second sector did not yield a personal best time and Hulkenberg failed to improve on his first effort and remained eighth, which left him vulnerable to the Racing Bulls and Alpine of Pierre Gasly.
All three did go faster than him and Hulkenberg was subsequently eliminated in 12th, one tenth away from the Q3 cutoff, with Bortoleto 13th. (But with that back-of-grid engine penalty.)
Gasly appeared to have hauled the Alpine into Q3 once again before late laps from the Racing Bulls duo dropped him out of the top 10, 0.032s away from Lawson's time, though Lindblad's penalty for a change of internal combustion engine means Gasly will start 10th.
He was more than six tenths faster in Q2 than Alpine team-mate Franco Colapinto, who was 14th.
Fernando Alonso had been inside the top-16 Q2 progression mark in all three practice sessions and he made good on that by making it out of Q1, despite a fire breaking out at the rear of his Aston Martin as he headed out for his final attempt in that session.
Alonso was able to continue and though he looked the slowest of the 16 cars in Q2 he was rewarded for improving on his final lap when Ollie Bearman had his final effort scrubbed off for a minor track limits breach exiting the Turn 11 hairpin, which dropped him from 13th to the bottom of the Q2 order.
Williams's painful double exit
Esteban Ocon had been faster than Haas team-mate Bearman on their first Q1 runs, but did not improve on his second attempt then failed to find enough time to beat Alonso's time and was eliminated in 17th.
That fate also befell Lance Stroll, who'd been on his Aston Martin team-mate's tail on Friday but shipped more than four tenths to Alonso in the end in Q1.
But Williams's miserable weekend continued, with both cars more than half a second off the pace needed to make it out of the session.
Carlos Sainz was the faster of the two in 19th despite failing to improve on his final lap, while Alex Albon rued running unnecessarily early before the end of the session.
"What a ****show," he said after qualifying 20th, as the lap went away from him in the final sector when he slid through Turn 18, the final part of the multi-apex right-hander. "Even worse, I don't know what's going on."
Less than a tenth of a second separated the two Cadillacs at the rear of the order, though it was again Sergio Perez who was faster than Valtteri Bottas - who it emerged on Saturday at Austin is not yet guaranteed to race for the team in 2027.
Classification - Q3
1 Kimi Antonelli (Mercedes) 1m34.035s
2 Max Verstappen (Red Bull) +0.179s
3 Isack Hadjar (Red Bull) +0.215s
4 Charles Leclerc (Ferrari) +0.232s
5 Lewis Hamilton (Ferrari) +0.276s
6 George Russell (Mercedes) +0.441s
7 Oscar Piastri (McLaren) +0.768s
8 Lando Norris (McLaren) +1.014s
9 Arvid Lindblad (Racing Bulls) +2.014s
10 Liam Lawson (Racing Bulls) no time
Q2
11 Pierre Gasly (Alpine) 1m35.080s (+0.022s to P10)
12 Nico Hulkenberg (Audi) +0.078s
13 Gabriel Bortoleto (Audi) +0.611s
14 Franco Colapinto (Alpine) +0.642s
15 Fernando Alonso (Aston Martin) +0.738s
16 Ollie Bearman (Haas) +0.951s
Q1
17 Esteban Ocon (Haas) 1m36.531s (+0.291s to P16)
18 Lance Stroll (Aston Martin) +0.146s
19 Carlos Sainz (Williams) +0.239s
20 Alex Albon (Williams) +0.436s
21 Sergio Perez (Cadillac) +0.902s
22 Valtteri Bottas (Cadillac) +0.992s