The Eels edged the Magpies 20-15 to consolidate second spot in the standings.
Both packs put their heads down and bashed away at each other.
It was a replay of last year's final and the margins were small.
Southern (38 points) blundered a lot of lineouts which certainly did not help. And Taieri (43 points) countered with some critical handling errors. But it was an otherwise quality, if not spectacular, match.
Veteran Taieri loose forward Brodie Hume, in his 186th game for the team, made his usual impact on the match. He was strong at the breakdown and made some good carries.
Hooker Brady Robertson opened the scoring in the fifth minute. He pounced on some loose ball from a lineout and dived over.
His opposite, Naryan Strickland, helped set up the reply when he bulldozed his way through several tacklers.
Openside Konrad Toleafoa eventually got across several phases later.
Taieri regained the lead midway through the half when lock Josh Hill went over following a nice build up.
The home team levelled the score 15-15 quarter of an hour into the second half when centre James Te Pairi muscled his way to the try line.
But Taieri edged in front again when fullback Joe Cockburn scored what proved to be the winner with the best part of 20 minutes remaining.
Southern fullback Mackenzie Haugh created some magic for the Magpies and put in some colossal punts, and Te Pairi had a tight game at centre. Veteran prop Michael Mata'afa made a lot of hard yarns in the close exchanges.
Hume was everywhere for Taieri. Caleb Leef had periods when he controlled the game nicely but also came up with a couple of fumbles.
And front-rowers Ben Mosa’Ati-Fosita and Cam Allan-McNeill shone as well.
At the North Ground Alhambra-Union led University 20-17 at the break.
It was the first time the Broncos (four points) had a halftime lead all season.
Their pack had parity and the signs were positive. But University (26 points) pulled away in the final quarter of the game to win 36-23.
Hooker Ricky Jackson bagged a brace of tries in an impressive outing. Midfielder Jermaine Pepe and first five Blake Forward enhanced their reputations as well.
For the Broncos, loosies Ben Kay and Tyron Pelasio were industrious.
Green Island upset Dunedin 28-19 at Kettle Park to strengthen their claims on a playoff spot. The win lifts the Grizzlies to 28 points. They remain in fifth place.
Dunedin (39 points) slipped back to third, but is already safely through to the top six playoffs.
Harbour holds on to sixth spot. It beat Zingari-Richmond (nine points) 36-12 at Watson Park.
Competition leaders Kaikorai (47 points) had a bye.
