Lewis Hamilton heaped the pressure on championship rival Nico Rosberg by claiming pole position for the Brazilian Grand Prix.
Hamilton has never won at Interlagos, but knows he must finish ahead of his Mercedes team-mate in Sunday's race to take the title battle on to the final round of the season in Abu Dhabi.
And the 31-year-old Briton edged out Rosberg in a nail-biting qualifying session here on Saturday to secure what could prove to be a pivotal pole as he bids to keep his slim championship hopes alive.
Ferrari driver Kimi Raikkonen will line up in third with Max Verstappen of Red Bull fourth on the grid.
Rosberg will be crowned Formula One's 33rd world champion on Sunday if he wins in Brazil for a third successive year.
But the German would appear to have his work cut out with Hamilton, a winner of the last two races in America and Mexico, maintaining his fine form.
Hamilton has never won at the birthplace of his boyhood hero and triple world champion Ayrton Senna, but the Briton has given himself every chance of breaking that duck with another fine performance on Saturday.
The heavy rain forecast for the one-hour qualifying session failed to materialise with Hamilton's quickest lap 0.102 seconds faster than his championship rival.
Hamilton and Rosberg traded blows in their final runs, but it was the Briton, courtesy of a better second and third sectors of this Interlagos track, who claimed the 60th pole of his career.
"I felt quite comfortable in qualifying as I have done all through the weekend," said Hamilton, who is wearing a one-off tribute helmet in honour of Senna this weekend. "Nico generally has been going quicker as the weekend has gone on, but generally I have had it covered."
Rosberg added: "Lewis was just marginally quicker in the end. Anyway, as we have seen this year, pole is not the guy who will necessarily win the race."
McLaren are enduring a testing end to the season. Off the track, their chairman and chief executive Ron Dennis is fighting a boardroom battle to keep his job, while on it, Jenson Button is struggling for pace, too.
Four years ago here, Button won his and McLaren's last race, but the Briton, who is heading for the Formula One exit at the end of the season, will start only 17th tomorrow.
"Yeah, we definitely sorted those problems out didn't we," a sarcastic Button said over the McLaren team radio.
The 36-year-old, who has been slow all weekend, was half-a-second adrift of his team-mate Fernando Alonso, who safely made it through to Q2 and latterly Q3 for the top-10 shootout, and will start 10th.
Later, speaking to Sky Sports, a glum Button added: "The car was well-balanced yesterday and today it's a completely new car. It's annoying."
Felipe Massa, the Brazilian veteran who came so close to winning the championship in front of his home fans back in 2008, will enter his final grand prix at Interlagos tomorrow. And the Williams driver, a two-time winner in Brazil, will line up in a disappointing 13th.
Elsewhere, Sebastian Vettel and Daniel Ricciardo will start fifth and sixth with Romain Grosjean an impressive seventh for Haas.