With just one round to go, Taieri has 78 points and an 11-point buffer over the rest of the field.
It is followed by Southern 67, University A 59, Dunedin 58, Harbour 49, Alhambra-Union 41, Kaikorai 38, Zingari-Richmond 38, Green Island 6, Pirates 6.
Zingari-Richmond regained the Bert Hellyer Trophy for the first time since 2008 when it beat Green Island 59-10 at Miller Park.
First five-eighth Josh Casey scored 32 points in Taieri's 72-10 win over Green Island and became the sixth player to reach 100 points this season.
The leading scorers are Peter Breen (Alhambra-Union) 172, Greg Dyer (Dunedin) 169, Cam Rutherford (Kaikorai) 145, Ben Patston (Southern) 115, Fletcher Smith (University A) 107 and Casey 103.
Dunedin 10
Harbour 5
Dunedin had the first use of the strong breeze and squally showers at its back, and bivouacked for most of the half deep in Harbour territory.
The Sharks only had one converted try to Trent Renata to show for their efforts by halftime but squandered at least three other try-scoring opportunities.
The Harbour pack was tigerish defensively and used the maul effectively to gain valuable metres and wind down the clock, and the home side looked a big chance of an upset when turning to play with the elements.
But Dunedin came out strongly in the second spell, controlling the first 15 minutes, and Renata kicked a valuable penalty to extend the lead.
Harbour got back into the game, and captain and hooker Pete Mirrielees was driven over after 20 minutes to score an unconverted try and narrow the gap to five. But that was to be the end of the scoring.
The Harbour players probably only had themselves to blame, as they gave up numerous penalties when on attack and had fullback Mateo Malupo sent to the bin for good measure.
For Dunedin, Renata and Hugh Blake were probably the best two players on the paddock. Winston Stanley was solid in the midfield and Hame Toma and Sam Anderson-Heather got through a mountain of work.
Harbour halfback Nick Ealey probably justified his impending selection in the Otago squad, while Hadleigh May and fellow loosie Charles Elton were the pick of the forwards.
Dunedin 10 (Trent Renata try; Renata con, pen), Harbour 5 (Pete Mirrielees try). Halftime: Dunedin 7-0.
University A 26
Alhambra-Union 10
Former New Zealand under-20 centre Fa'asiu Fuatai was outstanding as University A blitzed Alhambra-Union in the first half in boggy conditions at the North Ground.
The students scored all their points in the space of 22 minutes in the first spell before the second half became a scoreless war of attrition in the increasingly difficult conditions.
Fuatai's strong, incisive running and sound defence was a feature and he scored two tries, the first after he swooped on an accurate grubber kick from Stephen Fenemor and the second when he intercepted a pass and sprinted 65m.
Their other tries went to winger Kieran Parker, after a break by Fletcher Smith, and to Smith himself, after he ran at an angle to score in the corner.
Alhambra-Union scored first when centre Jason Emery won the race to a grubber from Peter Breen but that was its lot, despite its honest endeavours.
Halfback Nick Annear continued his fine form for University A, Smith and Fuatai were excellent in midfield and Matt Faddes was an accomplished fullback.
Sione Teu had a strong game from No 8, Nick O'Connell was a lively openside flanker and Sam Sturgess a fine leader while Tama Tuirirangi worked hard at tighthead prop.
The Alhambra-Union backs were well contained for the most part but the forwards competed well. Ben Pereira was outstanding from the openside flank, Graham Cashmore was robust at No 8, Mike Colville continued his consistent form at lock, Highlanders hooker Liam Coltman was good value and prop Tom Viggo added impetus when he came on in the second spell.
University A 26 ( Fa'asiu Fuatai 2, Kieran Parker, Fletcher Smith tries; Stephen Fenemor 3 con), Alhambra-Union 10 (Jason Emery try; Peter Breen con, pen). Halftime: University A 26-10.
Southern 24
Kaikorai 3
Southern adapted better to the conditions to convincingly beat Kaikorai at a cold and damp Bishopscourt.
The Southern forwards kept the ball tight and made inroads with the pick and go as they hammered the Kaikorai line for long periods in the first half.
Kaikorai's defence held, and when a breakout was made, Cam Rutherford kicked a penalty goal after 35 minutes to give Kaikorai a 3-0 lead at the break.
Southern had the wind at its back in the second half and wasted no time in turning its forward domination into points.
Hooker Ricky Riccitelli scored the first of his two second-half tries after just two minutes, following a sustained forward rush.
The lead increased to seven when fullback Bryce Hosie joined the forwards close to the line and used his speed to score a try after 12 minutes.
The game slipped out of Kaikorai's grasp when winger Josh Gordon scored, and Riccitelli scored the bonus-point try.
Others to stand out in the Southern pack were No 8 Lafaele Faamoe, who made ground with his strong runs and was difficult to stop, tighthead prop and locks Ryan Thompson and Tim Ferguson.
Kaikorai fullback Tony Ensor showed enterprise with his slick counterattacks from the back. The best Kaikorai forwards were flanker Kyle Harris and No 8 Nathan Hull with their strong tackling.
Southern 24 (Ricky Riccitelli 2, Josh Gordon, Bryce Hosie tries; Ben Patston 2 con), Kaikorai 3 (Cam Rutherford pen). Halftime: Kaikorai 3-0.
Zingari-Richmond 59
Green Island 10
A dominant forward pack paved the way for Zingari-Richmond's convincing win over Green Island at Miller Park.
The Zingari pack won the mud wrestle in a game that was played in slippery and difficult conditions. The forwards hunted as a pack and were able to make ground with the drive and the pick and go.
Zingari had a strong front row, in which tighthead prop Jesse Muir and hooker Masiu Akauloa played dominant roles.
The Zingari forwards controlled possession and territory and in the second spell kept Green Island pinned in its own half.
Halfback Josh Botting provided good service to his backs and midfielders Nathan Roberts and Lachie Moore were dangerous with the ball in hand. The strong-running Moore used his strength to crash over for two tries.
Green Island's mistakes proved costly and it turned over too much ball that was exploited by Zingari.
Zingari led 31-10 at the break and added 28 additional points in the second half.
The best players for Green Island were No 8 Hamish Finnie, halfback Tala Fagasoaia, first five-eighth Sam Eriepa and winger James Spooner.
Zingari-Richmond 59 (Lachie Moore 2, Stephen Scoles, Colin Enright, Steven Roberts, Chris Bell, Masiu Akauloa, Joe Gregory, Toroa Christie tries; Willie Ripia 7 con), Green Island 10 (Fapene Popoali'i try; Shane McNoe con, pen). Halftime: Zingari-Richmond 31-10.
Taieri 72
Pirates 5
First five-eighth Josh Casey proved a highlight in Taieri's 12-try haul in a one-sided contest in the O'Brien Cup match at Hancock Park.
Casey bagged a total of 32 points, including four tries, and played a pivotal role in another four scored by outside backs Kieran Moffat (two), Ben Miller and Kurt Schrader.
Casey's ability to spot the gaps kept the Pirates defence at breaking point. Moffat was a powerhouse at centre, and wingers Miller and Shannon Young were threats out wide, which created space for Schrader to enter the line from fullback.
Up front, prop Aki Seiuli, hooker Henry Parker and lock Mike McKee loomed as threats in close for Taieri, while loose forwards Brodie Hume and James Lentjes were instrumental in broken play.
Pirates was again well served by its tight five, with Hisa Sasagi and Sekonaia T-Pole leading the charge up front. Halfback Ben West worked well under pressure.
Taieri 72 (Josh Casey 4, Kieran Moffat 2, James Lentjes 2, Brodie Hume, Ben Miller, Mike McKee, Kurt Schrader; Josh Casey 6 con), Pirates 5 (Mark Booth try). Halftime: Taieri 36-0.
