The students beat Alhambra-Union 38-12 and pushed it out of the top four by scoring six tries.
Taieri still leads the competition with 35 points, followed by Southern 33, Dunedin 32, University A 26, Alhambra-Union 22, Kaikorai 21, Zingari-Richmond 17, Harbour 16, Pirates 2 and Green Island 0.
The injury toll has played havoc with teams such as Alhambra-Union and Kaikorai, which won their first four games but now do not have the resources to be competitive against the top teams.
Alhambra-Union has lost its past three games and Kaikorai its past four.
Taieri scored 13 tries when it beat Pirates 79-20 and is one of only 10 teams to score 13 or more tries in a premier club game this century.
Southern 31 Kaikorai 18
Hooker Ricky Ricciteli played a decisive role in Southern's commanding 31-18 win over Kaikorai at Bathgate Park.
He moves close to the ground, which makes him skilled with the pick and go that he used to telling effect against Kaikorai.
Southern has a big pack and No 8 TJ Ioane was always a threat off the back as well as a skilled link player.
Halfback Frae Wilson distributed the ball quickly to backs and this helped the strong midfield of Tei Walden and Hanipale Galo cause headaches for the Kaikorai defence.
Kaikorai was on top for the first 15 minutes but met a rugged Southern defence kept it out.
Kaikorai made a lot of effort but the final pass let it down and it was not able to finish.
The best Kaikorai players were prop George Hendry, flanker Marcus Balchin, the inside pairing of Josh Renton and Matt Te Tana and wing Bryce Morgan.
Te Tana scored 13 points and the quick-thinking Morgan scored a try.
Kaikorai led 3-0 after 15 minutes but Southern then used its forward strength to score four tries and lead 24-8 at halftime.
Southern 31 (Bryce Hosie, Hanipale Galo, Byron Dodge, Adam Knight, Nasoni Havea tries; Ben Patston 3 con), Kaikorai 18 (Bryce Morgan, Matt Te Tana tries; Te Tana con, 2 pen). Halftime: 24-8.
Dunedin 27 Harbour 24
This pulsating clash was in doubt until the final minutes. It was a massive physical encounter strewn with big hits and crunching tackles.
Dunedin scored two converted tries inside the first 11 minutes. Winston Stanley went over after latching on to a kick through from winger Tim Tolovai and Hame Toma, possibly the game's best player at No 8 for Dunedin, pushed off a couple of weak tackles and scampered 30m.
Harbour got back into the game by holding on to possession for large chunks of time and was rewarded with a penalty to halfback Nick Ealey and a nice try to five-eighth Joe Collins.
Harbour let Dunedin back into the game late in the half with a try against the run of play to fullback Rowan Mckenzie, who kicked over the defence, retrieved and went over, and Dunedin led by 11 at the break.
The Harbour forwards dominated the second spell and tries to hooker Peter Mirrielees and Aleki Morris came through constant pressure on the Dunedin line. All Dunedin had to show for most of the half was a solitary penalty to rookie 18-year-old first five-eighth Greg Dyer.
It was 24-all with five minutes to go and whoever blinked first would lose. Harbour gave away a blatant penalty by replacement loose forward Ben Whale 40m out in front of the posts. Dyer calmly slammed over the penalty amid numerous duck calls to win the game for Dunedin.
For Dunedin, Toma was a colossus and was ably supported by bantamweight loose forward Nick Peacock and the tireless Hugh Blake. Winston Stanley and the 100-game blazer man Tumua Ioane superbly marshalled the defence, which won Dunedin the game.
For Harbour, lock Charles Elton was far and away the best.
Ratu Dawai was explosive with ball in hand. Nick Ealey was very composed and combative at halfback.
Dunedin 27 (Rowan McKenzie, Winston Stanley, Hame Toma tries; Greg Dyer 3 con, 2 pen), Harbour 24 (Aleki Morris, Joe Collins, Pete Mirrielees tries; Nick Ealey 3 con, pen). Halftime: 21-10.
University A 38 Alhambra-Union 12
University A capitalised on its opportunities much more efficiently to beat Alhambra-Union comprehensively at the University Oval.
The students scored six tries to two and achieved their four-try bonus point in 54 minutes against an Alhambra-Union team which had plenty of spirit but whose execution let it down.
Poor passing, handling and option-taking, too many turnovers and the conceding of needless penalties when on hot attack plagued Alhambra-Union.
It was a stop-start game, particularly in the first half, in which the highlight was a fine individual try by New Zealand under-20 lock Josh Dickson.
It was a much more lively second spell and University A made the game safe at 26-0 before Alhambra-Union dominated territory for most of the last quarter and was rewarded with tries to fullback Corey McFadzean and wing Colin Davies.
Dickson ruled the lineouts for University A, locking partner Hamish Walker had a fine all-round game and Nick O'Connell and Dillon Hunt were prominent in the tight-loose.
Wai Koia was a nippy and hard-working halfback, Shea Tucker ran strongly in midfield and centre Matt Faddes showed his class with a brilliant individual try.
Alhambra-Union lacked nothing in endeavour. Tom Viggo and Harley Iraia were tigerish workers in the front row and Mike Colville had a good all-round game at lock.
Caleb Gray ran with effect from halfback, Peter Breen tried hard to get the backline going but there was a lack of rhythm before Alhambra-Union finally broke down the student defence in the last quarter.
University A 38 (Wai Koia, Josh Dickson, Shea Tucker, Hamish Walker, Matt Faddes, Kieran Parker tries, Mitchell Purvis 4 cons); Alhambra-Union 12 (Corey McFadzean, Colin Davies tries, Peter Breen con). Haftime: 12-0.
Taieri 79 Pirates 20
Halfback Will Cosgriff played a key role as Taieri scored 13 tries to beat Pirates 79-20 at Peter Johnstone Park.
His speed to the breakdown and his swift clearance enabled the talented backline to exploit the breaks out wide.
Taieri used width in its attacks, probed gaps and kept recycling the ball until the gaps appeared.
It played at pace and the forwards, especially the loose forwards, linked with the backline to sustain the continuity of the attacks.
Play was efficiently directed by first five-eighth Michael Collins with long passes creating gaps out wide.
Centre Kieran Moffat displayed good judgement and silky skills and fullback Glen Beadle used his pace to join the line and score three tries.
His third try was a gem. Backs and forwards combined in an attack from halfway. The ball passed through seven sets of hands in quick succession before Beadle scored close to the posts.
Taieri scored six tries in the first spell to lead 36-6 at the break and added seven more tries in the second spell.
The best Taieri forwards were flanker Brodie Hume and lock Mike McKee, who made six clean takes in the lineout.
First five-eighth Craig Sneddon and midfield back Silapa Halanghau were the best Pirates backs and hooker Sokonaia T-Pole and lock Jared Williams were the best forwards. Williams made seven clean lineout takes.
Taieri 79 (Glen Beadle 3, Todd Ford, Kieran Moffat, Kori Rupene, Brodie Hume, Jarrod Graham, Craig Kippenberger, Shannon Young, Michael Collins, William Tagicakibau 2 tries; Collins 7 con), Pirates 20 (Sokonaia T-Pole, Hisa Sasagi tries; Craig Sneddon 2 con, 2 pen). Halftime: 36-6.
Zingari-Richmond 33 Green Island 18
A three-try bag to second five-eighth Lachie Moore set Zingari-Richmond up for a 33-18 victory at Montecillo.
Well-served from the inside pairing of halfback Josh Botting and first five-eighth Michael Paulin, Moore was again in sublime form with his ability to cut through the defence and create space.
Unfortunately, the good work from the Zingari-Richmond pack and its inside back trio was let down by dropped passes that kept Green Island in the game.
Both sides were guilty of handing back a hard-fought territorial advantage through penalties.
With the game locked up at 13-all with 30min to go, after Zingari-Richmond surrendered its 10-3 advantage at the break, lack of discipline crept into what was a messy, error-ridden affair.
Not until Zingari-Richmond lost two of its forward pack, Jesse Muir and Joe Gregory, to the sin bin did it start to play to a game plan, running in four tries to secure the victory.
This proved just reward for the journeyman-like performance from Zingari-Richmond lock Joe Latta, who was dominant at the lineout and secured eight clean takes. Another to stand out in the pack was captain Chris Bell, who was ever efficient at No 8 and in broken play.
Fullback Shane McNoe stood out for Green Island at fullback, was ably supported by centre Hayden McBride. In the pack, Luke Johnstone was full of work on the openside flank and his work was complemented by lock Jamie Waller, who proved solid and reliable in the tight.
Zingari-Richmond 33 (Lachie Moore 3, Chris Bell, Colin Enright tries; Michael Paulin con, 2 pen), Green Island 18 (James Spooner, Hayden McBride tries; Shane McNoe con, 2 pen). Halftime: 10-3.