Hooker Jason Macdonald left the field with an ankle injury when Taieri beat Pirates 25-20 to gain its first win of the season, and halfback Sean Romans injured his hamstring when helping University A to a 36-25 win over Alhambra-Union.
Midfield back Jayden Hayward came through unscathed when Zingari-Richmond was beaten 19-6 by Kaikorai.
Southern and University A remain unbeaten and share the lead in the competition after three rounds.
The solid Southern combination ground out a hard-fought 21-8 win over defending champion Dunedin.
The points after three rounds are: Southern 14, University A 14, Harbour 10, Pirates 9, Kaikorai 8, Taieri, Alhambra-Union 6, Dunedin 4, Zingari-Richmond 0, Green Island 0.
University A 36 Alhambra-Union 25
No 8 Paul Grant was in dominant form and played a key role in University A's win over Alhambra-Union at the North Ground.
Grant was dangerous with the ball in hand and broke the advantage line with his powerful running.
He set up good second-phase ball for his forwards or linked with the backs and played a key role in three of the students four tries.
It was a break by Grant from halfway that led to the first try when first five-eighth Chris Noakes sped away to give the students an 8-0 lead after five minutesThe students looked set to take complete control but a spirited Alhambra-Union side fought back and levelled the score when fullback Peter Breen scored four minutes later.
It was a see-sawing game after this.
The students pulled away and led 16-8 at the break after they scored the best try of the game.
Halfback Sean Romans burst down the short side from a scum at halfway and linked with fullback Matt Faddes.
Loose forward Brad Cameron was up in support and Grant used his strength to score the try.
The pattern continued after the break with Alhambra-Union clawing its way back to twice close the gap to four points before University A pulled away again.
The student pack did the basics well with its strong scrum, tidy line-out and the vigour of its loose trio of Grant, Cameron and Hoani Matenga.
Romans and Noakes were a potent inside-back combination and Liam McGrath was solid in the front row.
Noakes kicked six goals from eight attempts to score 21 points.
It was the vigorous defence of Alhambra-Union that kept it in the game.
Props Liam Coltman and Scott Manson were vigorous tacklers around the fringes and Jone Puamau and Paula Kinikinilau were solid on defence and dangerous on attack in the backline.
Puamau kicked three goals from three attempts when he took over the kicking role in the second spell.
University A 36 (Matt Faddes, Chris Noakes, Hoani Matenga, Paul Grant tries; Noakes 2 conversions, 4 penalty goals), Alhambra-Union 25 (Peter Breen, Paula Kinikinilau, Jone Puamau tries; Breen penalty goal, Puamau 2 conversions, penalty goal).
Halftime: University A 16-8.
Referee: Tim Baker.
Southern 21 Dunedin 8
Southern won the game in the first half when it dominated possession and led 5-3 playing into a 20-point gale at Kettle Park.
The Southern forwards gained 85% of the ball and it was kept tight in the forwards for the first spell.
The inside pairing of Lewis Hancock and Julius Glasson controlled the ball and fed it back into the forwards.
Dunedin was not able to get hold of the ball.
The only try of the spell came from a mistake by Southern fullback Hamish Buick when his clearing kick went up in the air.
But fortune favoured Southern because the ball bounced awkwardly and eluded the Dunedin defenders and ended in the arms of Southern winger Nik Tupaea, who sprinted 40m for the try.
Dunedin monopolised possession when it played into the wind in the second spell and took the lead, 8-5, when prop Keith Cameron scored after a rolling maul.
Two penalty goals by Glasson took Southern back into the lead 11-8 and it added two tries in the last 10 minutes.
The first came from skilled play by Glasson, who sent a wide pass for winger Greg Zampach to score wide out, and fullback Hamish Buick scored in the last minute after Dunedin turned over ball 40m out.
Southern was a solid unit in the forwards with loose forwards Sam Crompton and Carl Anderson and lock Uili Kolo'ofai playing impressively.
The best Dunedin players were Will Henry and Kelsey Miller in the front row and Robbie Smith at halfback.
Southern 21 (Nik Tupaea, Greg Zampach, Hamish Buick tries; Julius Glasson 2 penalty goals), Dunedin 8 (Keith Cameron try; Robbie Smith penalty goal).
Halftime: Southern 5-3.
Referee: Doug Rodgers.
Taieri 25 Pirates 20
Taieri muscled up in the forwards to claim a deserved breakthrough win of the season in front of an appreciative home crowd at Peter Johnstone Park.
Pirates dominated the scrum, where veteran props Shane Parata and Daniel Johnson showed all their guile and power, and won its share of line-out ball.
But Taieri's edge was in the loose forwards, where No 8 Charlie O'Connell and flankers Jeremy Corliss and Nathan Young hunted the ball with aggression and precision.
The sides went try-for-try in an entertaining first half, highlighted by the first of Taieri fullback Jared Campbell's two tries, scored after a deft behind-the-back pass from Todd Ford, and a 50m breakaway try from Pirates winger Jeremy Cave.
Taieri took control of the game five minutes into the second half when O'Connell appeared with the ball from a ruck and Campbell was on his shoulder to score.
Pirates struck back late with a try to replacement lock Brad Ross and had a couple of reasonable opportunities to steal the win, but Taieri's resolve held.
The backs were evenly matched, with second five-eighth Andrew Reid taking intelligent options for Taieri and both Cave and fullback Kieran Fowler looking potent at times for Pirates.
Taieri 25 (Jared Campbell 2, Jeremy Corliss tries; Hayden Parker 2 conversions, 2 penalty goals), Pirates 20 (Warren Kearney, Jeremy Cave, Brad Ross tries; Kieran Fowler conversion, penalty goal).
Halftime: Taieri 17-15.
Referee: Liam Scanlon.
Harbour 27 Green Island 0
Powerful centre Siaosi Folau was in blockbusting form as Harbour comprehensively beat Green Island at windswept Watson Park.
Folau's powerful running from centre yielded him two tries and he was the fulcrum of many Harbour attacks.
Harbour played textbook rugby into a howling southerly to lead 22-0 at halftime, attacking Green Island through the middle and at close range around the fringes with good ball control.
But it lost its momentum in the second spell when it was too ambitious in the wind and long cut-out passes were either dropped or floated out of control.
Green Island's defence also tightened and it deserved a consolation try as it hammered away on attack for the last 10 minutes.
Johnny Legg controlled play intelligently at halfback for Harbour, Luke Shervey was outstanding on attack and defence from the blindside flank, Brad Griffiths was an industrious No 8, lock Graham Cashmore did excellent work in the line-outs and Peter Mirrieless was a combative hooker.
It was a fruitless day for Green Island but it never stopped trying.
Paul Butson was useful, first at halfback and later at first five-eighth, prop Andre Clark was unyielding in his efforts and hooker Frankie Elisara tried hard in his 100th game.
Harbour 27 (Siaosi Folau, 2, Iloa Lihau, Sam Ready tries; Craig Sneddon 2 conversions, penalty goal), Green Island 0.
Referee: Ross Barnett.
Halftime: Harbour 22-0.
Kaikorai 19 Zingari-Richmond 6
Kaikorai capitalised on three defensive errors by Zingari-Richmond to record a victory at Montecillo.
Honours from a scoreless first half were mixed.
Kaikorai locks Seko Kalou and Chris Brun controlled the line-out but Zingari-Richmond dominated the scrum, while both backlines were devoid of any variation.
The second half followed much the same pattern, but Zingari-Richmond's defence came unstuck in the opening minutes after the break, with Kaikorai flanker Mitchell Clarke left to shimmy a 15m path to open the scoring.
Two penalties to Johnny Noakes handed a 6-5 lead to Zingari-Richmond.
But tiredness took its toll in the final 10 minutes as Kaikorai stretched the Zingari-Richmond defence with expansive tries to wing Craig Baird and replacement Jayden Spence.
It is with some irony that the victory for Kaikorai could be attributed to players in an otherwise beaten forward pack, with Kensak Palepoi and Mitchell Clarke tireless in the loose and Kalou and Brun dominating the aerial battle.
Zingari-Richmond's best player was Jayden Hayward, who created and directed play from second five-eight superbly.
His defensive work was of a high standard and served as an inspiration to those around him.
Kaikorai 19 (Mitchell Clarke, Craig Baird, Jayden Spence tries; Cam Rutherford 2 conversions), Zingari-Richmond 6 (Johnny Noakes 2 penalty goals).
Halftime 0-0.
Referee: Steve Salton (Auckland).
