Lewis Hamilton's hopes of securing the world championship in style suffered a setback in Austin after he qualified only fifth for Sunday's United States Grand Prix.
Valtteri Bottas, who has to win here to stand any chance of taking the title fight to Brazil in a fortnight's time, secured pole position ahead of Ferrari's Sebastian Vettel.
Red Bull driver Max Verstappen will line up in third, with Ferrari's Charles Leclerc fourth on the grid.
Hamilton needs to finish only eighth to be certain of the title that will move him one above Juan Manuel Fangio and within striking range of Michael Schumacher's record haul of seven.
But the 34-year-old British driver will face a tall order to see out the title with his 11th victory of another world championship-winning campaign.
Hamilton, the sport's fastest man ever over one lap, has only four poles to his name this year, and he was unable to improve that tally here.
He was running down in fifth place ahead of the final runs, but failed to go any quicker and was forced to abort his last lap.
There were no such concerns for Bottas as he saw off Vettel by just 0.012 seconds to take his fifth pole of 2019.
"I am really happy," said Bottas, who is 74 points behind Hamilton with only 78 available. "It was a nice lap at the beginning of Q3. It is a good feeling."
Hamilton is notoriously difficult to beat in Austin, having won on five of his last seven visits to America, but here he finished three tenths down on his Mercedes team-mate.
It marked a scruffy session for the five-time world champion, who had earlier irked Verstappen.
Hamilton and Verstappen have been engaged in a war of words since last weekend's Mexican Grand Prix, and the duo almost collided here in Q2.
Hamilton moved to his left to overtake the Toro Rosso of Daniil Kvyat at Turn 19, with Verstappen then taking to the grass to avoid the Briton's Mercedes.
The Dutchman vented his anger at Hamilton in a strongly-worded radio message.
"It is his f****** problem, this, what is happening," said Verstappen. The stewards noted the accident, but took no further action.
Explaining the incident, Verstappen said: "We were all lining up to do our lap, and I had Daniil in front of me.
"We were slowing down to make space and Lewis drove by like nobody was there, and didn't care. I was like 'if you don't care, neither do I'. Everyone was respecting each other and that is why it was such a close call."
British teenager Lando Norris was the surprise name at the top of the time chart in Q1. The 19-year-old eventually settling for eighth on the grid, one spot behind Carlos Sainz in the sister McLaren.
Alex Albon will line up in sixth place for Red Bull. Renault driver Daniel Ricciardo is ninth on the grid.