Coleraine 0-1 Donegal Celtic
Darren Murray tapped the ball home after Gavin Cullen fumbled Eamon McAllister's cross from the right in the 67th minute to give DC victory.
The visitors had the chance to take an early lead but goalkeeper Cullen saved Paul McVeigh's penalty after Howard Beverland had handled inside the area.
McVeigh's close-range header was cleared off the line and Robert Robinson saved from John Watt.
Curtis Allen clipped the post with a 30-yard free-kick for Coleraine.