Calum Elliot scored twice against Annan at Stark's Park to seal Raith Rovers' place in the Ramsdens Cup final.
The Division Two side were on the back foot when striker Peter Weatherson knocked man-of-the-match Joe Cardle's free-kick past his own goalkeeper Kenny Arthur in the opening minute.
Former Hearts striker Elliot added a second for the Championship side and fired in a third with a minute to go.
Rovers will play Stenhousemuir or Rangers in the final.
Those teams meet at Ochilview on 29 October in a match that will be shown live on BBC ALBA, with the final scheduled for Sunday 6 April.
Raith: McGurn, Thomson, Paul Watson (Donaldson 46), Hill, Booth, Anderson (Callachan 83), Moon, Fox, Cardle, Spence, Elliot (Smith 90).
Subs Not Used: Laidlaw, Vaughan.
Annan Athletic: Arthur, Watson, Weatherson, Swinglehurst (Bradley 80), Andrew Mitchell, Steven Black, Flynn, Chisholm, Hopkirk, Davidson (Todd 61), Brannan (Moffat 90).
Subs Not Used: Alex Mitchell, Jardine.
Booked: Weatherson, Flynn, Steven Black, Andrew Mitchell.
Referee: Kevin Clancy