The 34-3 win means Morgannwg will now face Coleg Sir Gar in the Millennium Stadium final next Wednesday afternoon.
Three first half tries, following sustained forward pressure, saw Morgannwg lead 15-3 at the break. Hemi Barnes, Jack James and Matthew Jeczalick were the scorers and although Owen Howe had given Llandovery the lead with a penalty, the score line was a fair reflection of how the game had gone.
The scoring continued after the break, wing Jack Huntley, fly-half Jared Evans and full back Tom Mcaloon showing Morgannwg are more than just a big forward pack with some superb tries.
Despite the final score, it was Llandovery College who dominated the early proceedings. Howe may have put an early shot at goal wide but the centre was running some dangerous lines for the home side as they continued to have most of the early possession.
Their control was rewarded as Howe was successful with his second penalty attempt but the response of Coleg Morgannwg must be applauded.
The visitors proceeded to use their obvious dominance in the tight to score three quick first half tries, the front five of the men in blue particularly impressing. No. 8 Barnes was the first to benefit, crashing over after Morgannwg were initially held up from their first driving line-out. Two further scores followed before the break as Morgannwg's pack proceeded to get on top.
From another line-out, captain James emerged with the ball and lock Jeczalik added a third in similar circumstances. Fly half Jared Evans was unable to convert each score but at half time, his side's dominance had been rewarded with a 15-3 lead.
If the first half had been about Morgannwg's forwards, their backs showed just how dangerous they can be with their fourth try minutes into the second half. Aled Summerhill was the creator, his break and deft hands in the tackle allowing Huntley, on his opposite wing, to cross in the left hand corner.
The conversion from Evans was again awry but at 20-3 down, Llandovery faced an uphill battle.
Sadly for them, it soon got worse. Evans hadn't had the best day with the boot but he'd released his outside backs effectively when the time was right. It was the fly half himself who then added the fifth try, racing through after Huntley and Tom Mcaloon had exchanged passes.
Morgannwg were now cutting loose and it was then Mcaloon's turn to score, the full back finishing off a huge overlap in the corner.
Evans converted both scores but the visitors had long since secured their place in the final at the home of Welsh rugby.