From the very first minute when Mark Poland scored a sensational goal Down were by far the better team throughout.
Kerry finished the game with 14 men after Donnacha Walsh was sent off in the second half.
This may mark the end of this Kerry team which had appeared in the past six All Ireland finals.
Kerry closed to within three points midway through the second half but Down scored seven points without reply.
It also marked the fifth time in a row that Down have defeated Kerry in championship matches.
Down now meet the winners of Kildare and Meath in the All Ireland semi final.
Martin Clark of Down was named the man of the match.