Vettel would need to finish in fifth place or worse to give his Spanish opponent any chance of lifting the drivers' trophy.

The German set a best qualifying time of 1 minute 12.760 seconds on the 4.3-kilometer (2.7-mile) Interlagos course, enough to put him four places clear of Alonso.

Britain's Lewis Hamilton took pole position, outpacing by one-tenth of a second his McLaren-Mercedes team mate and compatriot Jenson Button, who starts Sunday's race in second place.

Germany's Mark Webber will start third in the grid as his Red Bull colleague Vettel competes for a third drivers' title.

Annoyance and optimism

Vettel expressed his disappointment while remaining upbeat about Sunday's race.

"This placing annoys me," he said. "It was not quick enough and I know I could have done a little better."

"In the end we have to be happy with fourth place. There are enough examples of it being possible to win from fourth place."

While the qualifying results result give Vettel a clear advantage, Alonso needing to make up considerable ground from position eight in the grid, the forecast of rain could open up the field.

"Everything is possible and anything can happen," said Vettel. "We have to have our eyes open."

Alonso would need a podium finish - and some bad luck for Vettel - to win the title.

rc/sej (AP, AFP, Reuters)