Its Mas Que Nada by Sergio Mendes & Brasil '66 and it is on the original soundtrack, its track number 5
you can listen to the whole song here.....I've checked this link it works fine
http://www.sideload.com/cb/track/?id=93783
just click listen to track and it will play without downloading anything
(you may have gotten confused listening to the sample on most places because it opens with lyrics then goes into the funky beat with the oh ahhh ahaha stuff)