The visitors young side was no match for the Tangerines who controlled yesterday afternoon's fixture at Gayfield from almost start to finish.
Left-back Danny Grainger started off the procession and ended it by scoring the first and the last.
Just three minutes were on the clock when the former Gretna defender headed home a Ryan McCord corner from the right.
Despite dominating, it wasn't until midway through the opening period that the home side scored again, Greg Cameron's shot from the edge of the box taking a deflection before flying inside keeper's bottom left hand corner.
Fife minutes from the break, Fraser Milligan made it three going past two defenders before scoring with a drive from the edge which took a slight deflection.
Visiting keeper Kyle Allison brought off a terrific double save from first Ryan Dow and than David Goodwillie seven minuites after the re-start.
However, Allison had to admit defeat to Goodwillie ten minutes later when the Tannadice striker headed home McCord's inch-perfect right wing cross foir the fourth.
And three minutes later, Andis Shala scored the fifth from the spot after Caley substitute Danny Welsh had handled.
Nine minutes from time, Grainger completed the scoring with a superb individual goal, surging in from the left and leaving two Caley defenders in his wake to find the net with a flashing low angled drive.
Dundee United: McGovern, Milligan, Watson, Pope, Grainger, McCord, Cameron, Buaben, Dow (Allan 75), Shala, Goodwillie. Substitutes: Grant, Irvine, R Smith.