Harper (22) currently plays at No 2 position in the Southland men's team and has a string of successes before this win in the Otago event.
Hamish Ireland (Otago) beat his clubmate Brandon Hodgson on the final green in a close-fought final to win the senior plate while Chris Snow (St Clair) won the senior B event.
Brent McEwan, the Otago No 1, had a forgettable weekend but finished in style, winning matches in the senior B plate by impressive margins.
Schoolboy golfers Scott Mitchell (St Clair) and Anthony McCullough (Chisholm Park) became the intermediate and junior champions respectively while Murray Edgar (Otago) took top honours in the masters (over 40) event.
But the match of the day was the senior final, with Minty taking first blood winning the second hole when Harper came up short and failed to get up and down.
But Minty's lead was short-lived when Harper drove on to the third green and two-putted for a birdie 3 to square the match.
Harper went ahead on the next hole with a deadly pitch and went two ahead after the sixth when Minty's drive finished in the left side trees.
Minty finished short at the par 3 seventh and made a bogey four which increased Harper's lead to three.
Minty reduced the lead to two, sinking a 12m putt for a birdie 3 on the ninth green.
He looked to be on the comeback but his 2m birdie putt slid past the cup on the 10th green.
Harper went three up again with a birdie on Tipperary but missed the 14th green to the right and the margin was back to two.
The scores oscillated between two and three with Minty birdieing the 16th to keep the game alive.
Harper's conceded birdie on the wet 17th green gave him the match and the title.
