Brazilian striker Jo, on loan from City, levelled the scores with a close-range effort in the 19th minute, although he would later limp off to add to David Moyes' worries.
Blackpool scored what proved to be the winner a little after the half-hour mark when Jason Euell raced down the left before firing past Howard.
David Moyes told evertonTV: "It wasn't very good, so we're disappointed. I was disappointed in the performance and the attitude in the first half, all round it was well below what we expected."
The manager was buoyed by the attitude of his senior players after the game, but added: "I think they should all see it - there's importance in every game and maybe one or two should have recognised it before the game started."