Rosberg will take his first championship if he wins Sunday's penultimate race of the season.
Lewis Hamilton stormed to pole position at the Brazilian Grand Prix on Saturday with Mercedes team mate and title rival Nico Rosberg joining the triple Formula One world champion on the front row.
On a damp and overcast Sao Paulo afternoon, it was the 60th pole of the Briton's career, eight short of Michael Schumacher's record, and his first in Brazil since 2012 when he was at McLaren.
With his title on the line, it was also one of Hamilton's most important in a roller-coaster season marked by mechanical setbacks.
"This is the best I could have hoped for really coming into Brazil," said Hamilton who has never won at the bowl-like anti-clockwise Interlagos circuit. "It's always a track that I struggled at."
Ferrari's Kimi Raikkonen qualified third with Red Bull's Max Verstappen joining the 2007 world champion on the second row of the grid.
Ferrari and Red Bull also shared the third row with Sebastian Vettel and Daniel Ricciardo qualifying fifth and sixth ahead of a race that could well be wet, with showers threatened.
Hamilton, fastest in all three phases of qualifying, was already lapping quicker than Rosberg's 2015 pole position time of 1:11.282 in the second session and again lit up the timing screens in the final shootout with a best lap of 1:10.736.
The pole was a record 19th in 20 races this season for Mercedes.
Rosberg, winner from pole in Brazil for the past two seasons, was quicker than Hamilton at the first split on his final lap but then faded to finish with a best of 1:10.838.
"It was exciting qualifying, very close and Lewis was just marginally quicker in the end," said the German. "My lap was good as well, just not quick enough...missing that little bit out there.
"But it's OK. Pole isn't always the guy who then wins the race, I'm still optimistic for tomorrow."
Brazilian Felipe Massa, a double winner at Interlagos in his Ferrari days, qualified 13th for Williams in his final home race before leaving Formula One while Finnish team mate Valtteri Bottas starts 11th.
Jenson Button, who won the 2009 world championship at Interlagos for Brawn GP, qualified a disappointing 17th on the fourth anniversary of his and McLaren's last race win, also at the Sao Paulo circuit.
"We definitely sorted those problems out, didn't we?", the Briton said sarcastically over the team radio.
Button has one more race after Brazil before handing his seat to Belgian Stoffel Vandoorne.
Spanish team mate Fernando Alonso, whose two titles with Renault were won in Brazil, had a happier afternoon and will start 10th.