Oscar Piastri has snatched pole position from teammate Lando Norris to lock out the front row for McLaren in the Sao Paulo sprint on Friday.
Red Bull's Formula One leader Max Verstappen finished fourth fastest with Ferrari's Charles Leclerc to start third in a race that brings eight points for the winner.
Norris looked on course to take top spot throughout qualifying only to be gazumped by Piastri, with the Australian lapping the Interlagos circuit with a best time of one minute 08.899 seconds in his final throw of the dice.
Norris failed to improve on his final outing to allow Piastri to snatch the honours by just 0.029 seconds.
The Briton is 47 points behind Verstappen with 120 points still to be won.
Piastri, out of contention for the championship, will be expected to follow team orders and help Norris secure a maximum score, but anti-clockwise Interlagos has a tricky first corner.
"We'll see what the pace is like tomorrow for both of us," the 23-year-old Piastri told Sky Sports television. "I think first and second is the first objective and then we'll worry what order it is.
"I know that I'm not in the running for the drivers' standings, for the team it doesn't matter which way around we are.
"It would be nice to win but it's one point different and it's not the main race. We'll see. Lando needs the points in the drivers' standings a lot more than I do but of course I still want to win.
"It was a tricky session but I'm happy to have qualified on pole. My first lap didn't feel amazing so I knew I could improve, and my second lap felt good and the tyres held on. I'll try and win but we'll see."
McLaren are leading the constructor's championship but are only 29 points ahead of Ferrari, with Leclerc an obvious threat and teammate Carlos Sainz qualifying fifth and Mercedes' George Russell sixth.
Norris said he was surprised by the car's pace but he had made some mistakes at the end.
The Briton bristled at a question about Verstappen's position, and the championship battle.
"I hate these questions so much," he said. "I don't care about where he qualifies. For me it's just focus on my own job and that's it ... if he's first or last, I'll do the best that I can."
Verstappen, last year's winner in Brazil who has also won every sprint so far this year, said the bumpy surface had made the car difficult.
"They did the resurfacing but I think they actually made it worse to drive. It’s extremely bumpy everywhere, so that’s not good for our car.
"In all the bumpy areas the car is jumping around a lot and it’s costing me quite a bit of time," he said.
Alpine's Pierre Gasly will start seventh with RB's Liam Lawson eighth and Alex Albon ninth for Williams.
Britain Oliver Bearman, the 19-year-old standing in for the unwell Kevin Magnussen, completed the top 10 on the grid for Saturday's 100km race.
Mercedes' seven-times world champion Lewis Hamilton qualified 11th while Red Bull's Sergio Perez will start behind in 13th.
Neither Aston Martin made it through the first phase.
Regular qualifying for Sunday's main grand prix follows the sprint race.
