The Dunedin-based team surprised a lot of pundits and entered uncharted territory when it made it through to the semifinals on Saturday.
The surprises kept coming, with Southern beating Capital on penalties on Saturday to advance to the final.
But 30 seconds into the final, Auckland scored and led for the majority of the match until drag flick specialist Kane Russell found the back of the net to level the scores.
The game went to extra time and Auckland grabbed a golden goal shortly after the resumption to claim the trophy.
It was disappointing but Southern got very little mention in dispatches before the tournament. The team finished seventh last year and, since joining the league in 2004, had never made the top four.
So it has been a golden year for the team but Tarrant was struggling to see it that way when contacted for comment yesterday.
"Right now, I'm pretty gutted, to be fair," Tarrant said.
"The boys did so well this week and I'm pretty proud of them. It sucks we couldn't finish it off.
"We said we were aiming for the top four but we knew from there, if we made the top four, it was all on and we really wanted to get over that last hurdle."
Tarrant said his side was shocked to be trailing after about 30 seconds but the visitors rallied and had the better of long periods of the game.
"That was a bit of a shock. I can't even remember the goal.
"But we are a second-half team and we knew, if we defended well in the first half, they'd get frustrated and we could attack from there.
"The plan worked well but we just couldn't finish it off in extra time."
The men's final began at a cracking pace, Auckland ahead 1-0 inside 30 seconds when Marcus Child was left unchallenged as he pushed home from close range.
Southern kept itself in the contest with its persistence and determination against the odds.
From the second of two penalty corners, it won in the second half, Southern grabbed a 53rd-minute equaliser when Russell sent his drag flick high into the Auckland goal.
With no further scoring, the game went to nine v nine golden goal extra time.
From their first raid after just 18 seconds, Auckland scored. Jared Panchia had his attempt blocked but the ball found Tom Wickham's stick and he calmly slotted the winner and joined his team-mates in celebrating a third NHL title.
The Southern Women's team lost to Central 2-1 in a crossover match on Saturday but rebounded to beat Northland 2-1 in the playoff for seventh and eighth.
In the final, Canterbury's beat Auckland 3-1.
