Taieri will be attempting to win back-to-back titles and Dunedin is poised to win its third championship banner this century.
Both teams were tested in the semifinals. Southern led Dunedin 13-6 before the Sharks came back to win 29-23.
Taieri trailed University A 23-10 before it scored 20 unanswered points in the second spell to win 30-23.
The Taieri coach, Jason Macdonald, was relieved after the game.
"A hallmark of our performances this year has been our ability to play 80 minutes of footy.
"But it is not ideal for our supporters' hearts."
University captain and No8 Paul Grant played a major role in the students' second-round recovery after they languished at second bottom of the competition after eight games.
They won nine of their last 11 games.
Stephen Fenemor kicked eight points in the semifinal to finish on 235 points.
He became the third-highest scorer in a Dunedin rugby season since 1976, behind Daniel Soper (Dunedin) 260 and Tutere Williams (Zingari-Richmond) 249. Both those scores were in 1997.
Southern first five Ben Patston kicked five goals to score 13 points and finish the season on 181 points.
Dunedin 29
Southern 23
Dunedin overcame a nervous start and put its game together in the second spell to beat Southern in the first semifinal.
It was a nervous and jittery Dunedin team that panicked in the first spell.
They tried to spread the ball wide too quickly and kept dropping passes and making silly mistakes.
Southern had a simple and mistake-free game plan and led 13-6 at the break.
It was traditional Southern rugby.
It controlled the lineout with two-handed takes from Tom Franklin and Sam Gavigan.
It had a solid scrum and No8 TJ Ioane caused jitters when he broke the advantage line with his tearaway runs.
First five-eighth Ben Patston was the pivot in the backline with his controlled tactical kicking that tested the Dunedin defence and kept the initiative with Southern.
He kept kicking to the corners with long raking punts and strong following up by the Southern team created pressure.
The Dunedin return kicks and disjointed attempts to run the ball back gave Southern the advantage.
These tactics brought a reward after 28 minutes when an accurate kick to the corner was dropped by fullback Liam Edwards and the ball bounced into the hands of Southern wing Harry Uffindell, who was following up.
He scored his 10th try of the season to give Southern a 13-6 lead at the break.
Patston also landed his three shots at goal.
The Dunedin goal kicker Pera Gibbs kicked two penalties from five attempts in the first spell.
Patston kicked his third penalty in the first minute of the second spell to give Southern a 10 points buffer, 16-6.
The Dunedin tactics changed in the second spell when it got its game together and played with more composure.
Loose forwards Gareth Evans, Hugh Blake and Mitchell Zandstra attacked as a unit and the front row of Kelsey Miller, Sam Anderson-Heather and Chris King were the battering rams.
Dunedin finally broke Southern's iron grip after 19 minutes when wing Ashton Tuck burst up the left flank to the line.
The pack came in behind and after two more phases the ball was spread wide and second five-eighth Kai Daniel scored the try.
The key man in the backline was quick-thinking halfback Brad Weber, who passed accurately and was dangerous with his probing runs.
His quick thinking gave Dunedin the buffer it needed when he scored the decisive try after 33 minutes, running a penalty 10m out and catching the Southern defence napping.
It gave Dunedin an eight-point buffer and this was extended to 13 points when wing Gibbs picked up a loose ball 55m out and outsprinted the defence.
Dunedin had added 23 unanswered points in the second spell.
Southern, belatedly, attacked through its backs and scored a late try when Sam Gavigan crashed over after four phases.
Dunedin 29 (Pera Gibbs, Kai Daniel, Brad Weber tries; Gibbs con, 4 pen)
Southern 23 (Harry Uffindell, Sam Gavigan tries; Ben Patston 2 con, 3 pen)
Halftime: Southern 13-6.
Taieri 30
University A 23
Taieri was shell-shocked by the student's blitzkrieg attack when it was knocked to the canvas in the first spell.
University A led 23-10 at the break but was held scoreless in the second spell as Taieri accumulated 20 unanswered points to win the game.
A stern talk by captain and No8 Charlie O'Connell worked the miracle as Taieri gradually took control of the game.
The Taieri forwards kept the ball tighter and, as the team regained its confidence, it started using its game plan.
The gap was closed after five minutes when second five-eighth Ben Nowell burst into the student 22m and wing Kieran Moffat used his strength to run 14m for his second try.
First five-eighth Hayden Parker was the little general who controlled the game.
He demonstrated his peripheral vision by choosing the right moments for his tactical kicks.
He was also accurate with his goal kicking and landed five goals from his five attempts.
His crowning moment came after 30 minutes when he dropped a neat goal from 28m to level the scores 23-23.
It was the students who were getting jittery at this stage.
The winning try came after 31 minutes when University fullback Matt Faddes tried to counter-attack from his own 22m and was collared.
Taieri centre Michael Collins, who had played a sound defensive game, grabbed the ball and ran 22m for the try.
The Taieri defence was put on high alert as the students desperately attacked in the last few minutes. It took a rugged defence to keep them out.
The students were unstoppable as they attacked from the start and they scored two tries in the first four minutes to lead 12-0.
The first try came from a lineout close to the Taieri line when lock Sam Henry made a two-handed take and the pack drove to the line and prop Sam Buchanan grounded the ball.
The students attacked from the kickoff when lock Rob Verbakel grabbed the ball.
First five-eighth Stephen Fenemor burst through the centre and linked with No8 Paul Grant, who burst into the 22m, and wing Sam McLernon used his pace to score the try.
The students looked to have locked in a win when wing Sam McLachlan grabbed a loose ball and sprinted 20m for the try just before the break.
Key players in the student backs were halfback Nick Annear with his accurate delivery and darting runs down the short side, centre Fassiu Fuatai with his electric bursts through the centre and Guy Schwikkard with his decisive defence in the midfield.
Grant, the decisive forward, was dangerous with the ball in hand, mobile locks Henry and Verbakel controlled the lineout and prop Tama Tuirirangi was solid in the front row.
The best Taieri forwards were O'Connell, who led by example with his aggressive defence, and flanker Willis Scott with his spot tackling.
Moffat was the other back to excel with his strong defence and his ability to break tackles.
Centre Michael Collins displayed maturity and had a formidable midfield combination with Ben Nowell.
Taieri 30 (Kieran Moffat 2, Michael Collins tries; Hayden Parker 3 con, 2 pen, drop goal)
University A 23 (Sam McLachlan, Sam McLernon, Sam Buchanan tries; Stephen Fenemor con, 2 pen)
Halftime: University 23-10.
