Striker Ger Rowe headed home their first goal after just seven minutes when he latched onto an in-swinging Richie Baker free kick.
Baker was also involved in the second just before the break, running freely at the Leeds’ defence before playing midfielder Stuart Byrne through on Nigel Martyn, to slot the ball home from ten yards.
Shelbourne played a near full strength side with Leeds starting Irish midfielder Stephen McPhail, Nick Barmby and also new signing Jody Morris. Leeds eased off in the second half, mindful of the Premiership start next Saturday.
SHELBOURNE: Williams, Heary, Crawley, Rogers, Kenna, Hoolahan, Morgan, S Byrne, J Byrne, Rowe, R Baker
LEEDS: Martyn, Mills, Domi, Morris, Matteo, Camara, Barmby, McPhail, Sakho, McMaster, Wilcox.
Ref: D Hancock (Dublin)