Morris cut through the defence after a lineout take by lock Josh Dickson to score his try after 26 minutes.
He was always dangerous with the ball in hand and made the break for the next try by fullback Ben Miller four minutes later to give Otago Boys' a commanding 24-3 lead at the break.
The Otago Boys' pack was dominant in the scrum in the first half and prop Lachlan Landels had a powerful game.
No 8 Brodie Hume was able to breach the advantage line and the towering Dickson dominated the lineout with his two-handed takes.
Josh Renton was an efficient halfback and Michael Collins had class in the midfield with his rock-like defence and his ability to stand in the tackle.
It was a rejuvenated Waitaki Boys' that camped inside the Otago Boys' 22m for 10 minutes before No 8 Tui Katoa broke from a scrum to score the first try of the second spell.
Otago Boys' gave a polished display in the first half but the game lost its structure in the second spell and this suited Waitaki's marauding style.
A key player in the Waitaki Boys' second-half turnaround was openside flanker Jake Rhodes, who was a pest at the breakdown.
Jamie Robb was a skilful first five-eighth and cut through the first line of the Otago Boys' defence. Anthony Wetere-Sweet was a ferocious tackler in the midfield.
Otago Boys' 29 (Michael Collins, Ben Miller, Aleki Morris, Sean Conner tries; Sam Ellis 3 con, pen), Waitaki Boys' 8 (Tui Katoa try; Marc Fox pen).
Halftime: Otago Boys' 24-3.
