SAO PAULO, Brazil — Light rain fell at the Interlagos track Sunday morning and heavy showers were expected in the afternoon when Lewis Hamilton and Felipe Massa race for the Formula One title during the decisive Brazilian Grand Prix.

Thousands of fans lined up to enter Interlagos in the hope of celebrating Brazil's first F1 title since Ayrton Senna in 1991.

Massa, who grew up near Interlagos, will start from pole position with his Ferrari in the season-ending race, with points leader Hamilton fourth on the grid for McLaren.

Massa, who trails by seven points, has to finish first or second to have a chance of winning. Hamilton can become F1's youngest champion by finishing fifth or better, regardless of where Massa finishes.

The sun came out at times in the morning, but forecasters predict an 80 percent chance of thunderstorms around the start of the race at noon EST.

About 70,000 fans are expected at Interlagos, and the track was already nearly packed more than five hours before the race. Most of the fans were dressed in the red colors of Ferrari, and many carried banners supporting Massa — and some wishing bad luck to Hamilton.

Hamilton missed a chance to win the title in his rookie season last year by blowing a seven-point advantage over Kimi Raikonnen, Massa's teammate, in the last race.

The title this year would still make Hamilton the youngest champion at age 23. Renault's Fernando Alonso was 24 when he clinched the title in 2005.

Hamilton could also become the first British F1 champion since Damon Hill in 1996.