* Hamilton on pole in last race for McLaren
* Vettel starts fourth, Alonso seventh
* Maldonado handed 10 place penalty
* Schumacher 13th on grid for F1 farewell (Adds fresh quotes throughout, Schumacher 13th)
By Alan Baldwin
SAO PAULO, Nov 24 (Reuters) - Lewis Hamilton grabbed pole position in Brazil on Saturday for his last race with McLaren while Red Bull's Sebastian Vettel took a big step towards becoming Formula One's youngest triple champion.
Championship leader Vettel will start Sunday's season-ending race in fourth place, a position good enough to secure his third title in a row if he keeps it in what promises to be a rain-lashed affair at Interlagos.
Ferrari's Fernando Alonso, 13 points adrift of Vettel and the German's sole rival, has to finish on the podium to have any hope of taking his third title and the Spaniard has a mountain to climb from seventh on the grid.
Vettel, 25, made clear he would not be playing it safe despite his grid position.
"As soon as the lights go off I will try to attack the guys at the front. On top of that there might be things happening, with the weather forecast being what it is, so I won't be looking left and right to be honest," said the German.
Vettel will have Australian team mate Mark Webber starting alongside him in third place with those positions likely to be swapped soon enough.
Alonso qualified eighth but moved up a place when Venezuelan Pastor Maldonado, who was sixth, was handed a 10-place penalty for missing a weighbridge in the second phase of qualifying.
The stewards handed Maldonado a reprimand for the offence but also imposed the grid drop because it was his third reprimand of the season.
Alonso can also count on the support of Brazilian team mate Felipe Massa, who qualified fifth but is sure to let the title contender go past when the opportunity arises.
"Given how the last few races have gone, my chances of making it to the podium are still intact," said the 31-year-old Alonso. "In the dry we are not competitive, but in the wet the car performs well sometimes and we are a little more comfortable."
Hamilton's pole, the 26th of his career, was McLaren's first in Brazil since Mika Hakkinen in 2000 and the Briton will start next to Jenson Button in the team's 62nd front-row lockout.
"I think the weather will be tricky tomorrow, it will make it more of a lottery," said Hamilton, who is moving to Mercedes next season after what will be an emotional farewell to a team that has been part of his life since he was 13 years old.
"We've put ourselves in a really good position to do the best job we can do."
Qualifying started after a light rain shower and with overcast skies, but the track was drying through the session without a feared downpour.
Germany's Nico Hulkenberg, who was on pole at Interlagos in 2010 for Williams in weather-affected conditions, will start sixth in his last race for Force India before moving to Sauber.
Finland's 2007 champion Kimi Raikkonen put his Lotus in eighth place with Germany's Nico Rosberg in ninth for Mercedes and Force India's Paul Di Resta rounding out the top 10 after Maldonado's penalty.
Raikkonen's team mate Romain Grosjean was the big loser from qualifying after tangling with the HRT of Spaniard Pedro De la Rosa in the first phase and ending up 18th.
"I was behind Pedro for the whole lap, he had blue flags. I went to overtake him and I don't think he saw me, I braked as much as I could but we made contact," said Grosjean.
"In those colder conditions it was difficult to get the tyres up to temperature for the final lap."
Seven times world champion Michael Schumacher will start his last Formula One race in 13th place for Mercedes, ending a three-year comeback at the age of 43 and with little hope of waving goodbye from the podium.
"For obvious reasons, I am not particularly happy about the qualifying session today," he said.
"Coming from where I am does not make it easy but I will definitely try to fight my way up the field." (Reporting by Alan Baldwin, editing by Clare Fallon, Alison Wildey and Mark Pangallo)