Pamela wasted no time putting Brazil into the lead, opening the account after four minutes when she slotted home from close range on the end of a fine pass from Joyce. The South Americans' outstanding creator, Francielle, then added another goal five minutes from the interval when she squeezed the ball inside the far post after a fine bit of individual work.
The fancied and dominant South Americans, who have never finished outside of the top four at a women's U-20 showpiece, kept up the pace in the second half. Daiane made it 3-0 on the end of one of Leah's trademark, and wildly acrobatic, throw-ins in the 68th minute to put the result well beyond reach.
Ketlen and Wendoline Ortiz added a pair of goals in stoppage time as the Mexicans lost the plot and the Brazilians underlined their pre-tournament designation as favourites for a title run.
Brazil are likely to progress to the knockout rounds of Chile 2008, but a set of strange results on the final matchday could still see them thwarted. Similarly, pointless Mexico will most likely go out of the running, but are still technically alive ahead of their final game.