The Hawks led 20-10 at the break but ill-discipline saw them twice reduced to 14 men.
Pirates first five-eighth Craig Sneddon kicked five penalties and a conversion to help his side prevail 27-26 against Green Island, despite trailing 26-16 at the break.
University A demonstrated how hard it will be to beat this season with a 63-7 win against Alhambra-Union. The defending champion outclassed the home team up front in a nine try romp.
Taieri scrummed its way to superiority against Zingari-Richmond, winning 55-24.
The Colours picked up a bonus point for four tries, though.
Southern's Mika Mafi scored three tries in his side's 33-7 win against Kaikorai.
Dunedin 36
Harbour 34
The wind was a factor at Kettle Park but Harbour still managed to blow a 20-10 halftime lead.
The Hawks will be left ruing some poor discipline which saw both Naulia Dawai and Hale T-Pole both issued yellow cards.
Dawai was in the sin bin when Louis Tili scored a try for Dunedin in injury time to level the score 34-34. First five-eighth Tim Cossens drilled the conversion from near the sideline to clinch victory.
Harbour played with the wind in the opening half and scored tries through winger Sala Halaleva, hooker Sekonaia Pole and centre Aleki Morris.
Morris and Pole added one apiece in the second spell, as well.
Dunedin hooker Sam Anderson-Heather had a strong game and scored after his side had been hammering away at the Harbour line shortly before the break.
He barged over for his second following the resumption. Highlander Gareth Evans scored two second-half tries to help his side get back into contention.
Lock Harry Dodds stood out in the lineout for Dunedin, while former Green Island midfielder Fapene Popoali'i showed promise.
Evans delivered a quality performance, as was to be expected, Morris found space in the midfield for Harbour and halfback Tala Fagasoaia also impressed.
There were lots of missed tackles and errors during the game, though, so plenty to work on for both sides.
Southern 33
Kaikorai 7
Powerful Southern No8 Mika Mafi barged his way through the Kaikorai forward pack to bag three tries in an impressive early season display at Bathgate Park.
The hardworking Otago loose forward proved impossible to stop whenever he got close to the try line and has set a high benchmark for the other ball running forwards in the competition.
Magpies fullback Jono Hayes opened the scoring with a penalty in the eighth minute. His side had a stiff breeze behind it and had dominated possession. Mafi scored the opening try in the 15th minute.
He picked up the ball after about four or five phases and pushed his way over.
Southern added another through winger Rema Smith.
Kaikorai fullback Tony Ensor made an error clearing his line and Rema went over in the left corner.
Ensor made good, though. Right on the stroke of halftime he chipped ahead, regathered and dotted down under the sticks.
Southern led 16-7 at the break and dominated the second spell to win 33-7.
Hayes added an early penalty and Mafi added two more tries, almost carbon copies of his first effort.
Kaikorai loose forward Johnny Appleby was solid and Ensor, one blunder aside, showed some good touches.
Hayes was secure at the back for Southern and prop Shaun Stodart held up his side of the scrum. But Mafi was the star and has shot to the top of the try-scoring list.
University A 63
Alhambra-Union 7
University A made a statement with a 63-7 demolition of Alhambra-Union in a comprehensive display at the North Ground.
The defending champion paved the way for the large victory with a formidable performance up front.
Highlanders prop Daniel Lienert-Brown helped get his side's scrum moving forward. Locks Josh Dickson and Jack Sherratt provided some additional muscle.
Hooker Sam Sturgess kept busy and No8 Sione Teu carried the ball well. All that go-forward gave classy first five-eighth Fletcher Smith a very comfortable ride.
He used the extra time and space his forward pack created to ghost through gaps and basically run amok.
Midfield pairing Tim Murgatroyd and Shae Tucker benefited, scoring two tries apiece.
Replacement winger Taylor Haugh plucked the ball out of the air to set up a try for the athletic Dickson and showed some real gas whenever he got on the outside of a defender.
Smith scored the game's last try and it was quite an effort.
He can spot a gap from Mosgiel and ducked between two defenders, stepped the full back and outpaced the cover defence, to score under the posts.
It capped off a wonderful game in which he scored 23 points.
Alhambra-Union scored a consolation try when winger Adam Simpson swooped on the loose ball and scampered the best part of 70m to score, and centre Junior Vitale provided some good moments with two or three clever offloads.
Pirates 27
Green Island 26
Ringing the changes proved a master stroke by the Pirates management.
Pirates were labouring but found the energy to escape with a 27-26 victory at Hancock Park.
Green Island took just four minutes to open the scoring, through a try to first five-eighth Alex Barnsley.
It had starved Pirates of ball and ran its defence ragged.
The inclusion of Highlanders Jackson Hemopo and Ross Geldenhuys helped Green Island gain dominance in the forward exchanges.
It monstered Pirates at scrum time, paving the way for a rare four-try bonus point by halftime.
Geldenhuys proved hard to stop. His 40m run for the line to score had the Pirates defence parting like the Red Sea.
Minutes later Hemopo took the ball from the back of a scrum and passed inside to wing Sofele Tuigamala for the same result.
Trailing 16-26 at the break, the Pirates defence regrouped after stern words.
It kept Green Island scoreless throughout the second spell and fatigue was countered by ushering players off the bench.
The fresh legs proved vital in holding out a prolonged Green Island attack on the Pirates line in the final minutes of a match.
Taieri 55
Zingari-Richmond 24
Tighthead prop Aki Seiuli played a dominant role in Taieri's eight try, 55-24 demolition of Zingari-Richmond at Peter Johnstone Park.
He was strong on the drive and the pick and go and had the fitness to get around the paddock and score two tries.
But it was his strong scrummaging which made the difference and helped Taieri get on top of a tigerish Zingari-Richmond pack.
The decisive point in the game came in the last 10 minutes of the first spell, when the Taieri pack started to push the Colours back in the scrums.
Zingari-Richmond midfield back Marty Banks was quick to pounce on any Taieri mistakes and scored two tries to give his side the lead 12-3 after 24 minutes.
Taieri scored its first try from a scrum after 31 minutes and then took charge to score three tries and 19 points in the last 10 minutes of the first spell, to lead 22-12.
Three of Taieri's tries came from its dominant scrum.
The solid platform gave Taieri's slick backline the freedom to add five more in the second spell.
Willis Scott was aggressive at No8 and midfield back Ben Miller displayed slick footwork.
Banks was the best Zingari-Richmond back and flanker Tom Rowe was decisive in the lineout with seven clean takes.
Chris Bell was a workhorse at No8 and openside flanker Steve Roberts played his 100th premier match.
