Derry City 0 Cork City 1
A brilliant headed goal from Tim Kiely put Cork City into the Setanta Sports Cup final with a smash and grab raid at the Brandywell.
The win avenged Cork's FAI Ford Cup quarter-final defeat on penalties at the same venue last month.
In a game of precious few openings, the only goal came on 67 minutes.
Central defender Dan Murray found himself in the outside left position, but the skipper put over the best cross of the night and Kiely found the net with a brave header.
Derry's best chance of an equaliser came on 83 minutes when Niall McGinn's mazy run set up Barry Molloy, but the weak shot was straight at keeper Mark McNulty.
Cork, beaten finalists in 2006, will now meet Irish League leaders Glentoran in the final on Saturday, November 1, at a venue to be decided.