The final was always going to be close, with Ross (St Clair) at No8 in the Otago men's team, while Smith (Otago) was one place back as the team reserve for the South Island event last month.
Unfortunately Otago will be without the services of Smith in the new year as he has enrolled for a golf management course at the International College of Management in Sydney.
Both pupils are in year 13, so it was their last opportunity to contest the trophy, which a string of top players have won since its inception in 1967.
Hayden Robertson (Taieri Lakes) birdied the final hole to beat Sam Ballantyne by a margin of two in the plate event.
In the senior final, Smith made the early play, winning two of the first three holes to take the lead.
Ross birdied the par-3 fourth but Smith won the sixth and seventh with pars to open up a lead of three.
Ross birdied the par-5 eighth and went back to one behind with a birdie two on the 10th hole.
He also won the difficult 12th hole with a par 4 to square the match but he bogeyed the 14th to trail once again.
Ross made a par 5 at the long head-wind 15th to square the game, while Smith left a birdie putt at 16 short of the cup, losing the chance to regain the lead.
After halving the penultimate hole in pars the outcome came down to the final hole, with Smith's birdie three the difference.
