14 days for Powell at Fakenham
Powell's mount jumped the regulation last with a clear advantage, but rather than go to the left of the fence almost alongside the winning post, the seven-year-old went to the right and jumped the obstacle.
Powell appeared to realise his error approaching the fence but it was all too late for backers of the 5-4 favourite.
In the race proper, Peak Seasons - a winner at Leicester on Monday - rattled home to put his head in front of Roc De Guye right on the line and claim the spoils.
Speaking from Folkestone, Benny The Swinger's trainer Chris Gordon told At The Races: "It's just one of those things. It's one of those things that happens up there (at Fakenham) far too often. If only they dolled it off on the final circuit, so jockeys can't make a mistake.
"It's such a tight circuit. I'm not going to shout at the boy, I'll let his father (Brendan Powell senior) give him a bit of a rollicking.
"Brendan himself will be absolutely gutted about it, I'm gutted because I had a little bit, the owner is gutted.
"It's very upsetting but it's one of those things at Fakenham that's happened so many times. I think the track ought to try and do something so they can't go on the chase course."
Powell will be out of action December 4-17 inclusive.
Top-class filly The Fugue will finish off her 2012 campaign in the Longines Hong Kong Vase on December 9 before remaining in training next year.