Taieri chalked up its 16th successful defence of the Challenge Shield and remains unbeaten this season following a 25-15 victory over Southern.
Kurt Hammer provided the spark from halfback while the Scott brothers Willis and Mitchell were also instrumental.
Harbour brushed aside Alhambra-Union 45-22 but the competition's cellar dweller picked up a four-try bonus point as a consolation.
Former Highlander Neil Brew guided Zingari-Richmond to a 43-29 win against Pirates, while Kaikorai produced a strong finish to beat Green Island 47-17.
University A held off Dunedin to win 23-17 in the game of the round.
Dunedin blew several golden opportunities to snatch a win at the death.
University A 23
Dunedin 17
Dunedin started with a hiss and a roar, dominating territory and possession and led through three Lois Tili penalties.
But its nemesis throughout the game was the turnovers it coughed up and Varsity had the class and the pace to turn them into tries, which would ultimately win it the game.
Shae Tucker and Faasiu Fuitai were the benefactors in the first spell, as Varsity got numbers on the break and they finished them with aplomb to give Varsity a four-point lead at halftime.
The game was held up for 15 minutes at the break and moved to Logan Park after Dunedin flanker Harry Dodds got his head on the wrong side of a tackle. He was taken to hospital but has been cleared of a neck injury.
Varsity dominated the early part of the second spell and lock Josh Dickson popped up out wide to stretch his lanky frame out and score.
He scored again midway through the second half with an amazing burst of pace from 45m to give Varsity an 11-point lead and the game looked done - but nobody told Dunedin.
It fought back with two Rob Thompson breaks and eventually lock Mark Grieve Dunn muscled over in the corner to cut the lead to six.
Dunedin's big, powerful pack got back within striking distance but blew two gilt-edged opportunities through handling errors with the line at its mercy.
For Varsity, Josh Dickson and Dillon Hunt were its best up front.
Hame Toma and Grieve Dunn were the best of the Dunedin pack and Thompson and Leroy Van Dam were solid in the midfield.
Taieri 25
Southern 15
Veteran halfback Kurt Hammer was the fireball who played a key role in Taieri's successful 16th defence of the Challenge Shield.
Taieri won the trophy in 2014 and retained it at its Peter Johnstone Park bastion when it downed Southern 25-15.
Hammer played the role of a fourth loose forward with his tenacious tackling and dabs upfield with the ball.
The Scott brothers were the other key players in Taieri's hard-fought win against a Southern team that played powerhouse rugby in its bid to break the Taieri defence.
No8 Willis Scott cut down the big Southern marauders when they threatened to break the Taieri defence.
Fullback Mitchell Scott was dangerous on the counterattack and made the decisive break that led to Ben Miller's late try.
Lock Matt Davidson, in his 100th premier match, won his share of lineout ball and was a strong defender.
The other key Taieri defender was second five-eighth Kori Rupene.
Taieri led 10-8 at the break and came out blazing, with a sparkling four-phase attack, early in the second spell that stretched the defence and wing Vinnie Booiman scored in the corner.
The lead stretched to 10 points, 18-8, when centre Matt Whaanga kicked his second penalty after five minutes.
Southern dominated the next 20 minutes with blitzkrieg attacks by its big men that tested the Taieri defence.
No8 Mika Mafi, locks Ryan Thomson and Axel Hohneck and centre Hemaua Samasoni were powerful runners.
Samasoni, the best back, scored Southern's two tries.
He was supported by first five-eighth Josh Ioane.
Harbour 45
Alhambra-Union 22
Whenever Harbour got within rumbling distance its big forward pack went to work.
Hale T-Pole, Charles Elton and Ben Whale combined to dominate the lineout, and openside flanker James Tomkinson had a busy game.
But while Alhambra-Union struggled to match the Hawks' physicality, it showed some character, scoring two late tries to nab a four-try bonus point in what was otherwise a comprehensive win to Harbour at Watson Park.
Hawks centre Aleki Morris opened the scoring when halfback Tala Fagasoaia caught the defence napping with a quick tap.
He passed to Morris who partly slipped a tackle and reached out to score.
The second try was classic Harbour.
Prop Peter Mirrielees crashed over after the Hawks' pack got a lineout drive going and bulldozed its way towards the line.
Alhambra was guilty of not treasuring possession and too often had the ball knocked clear by some big tackles in the midfield.
It went to the break trailing 24-0 which was soon 31-0, after the team failed to number up on defence.
Harbour coughed up the ball from the restart and Alhambra-Union got on the board through an Adam Simpson try.
It was the first of four second-half tries for the visitors.
It owed its second to a wonderful clear out by loose forward Ben Tuiomanufili.
He blew several Harbour players off the ball and Legin Felix-Hotham scooped it up and ran 80m untouched to score.
Zingari-Richmond 43
Pirates 29
Former Highlander Neil Brew made a big impact in the middle of the park for Zingari-Richmond.
All roads lead to Rome and all passes went through Brew.
The strong midfielder was at the centre of the action, as the Colours ran most of their moves through the 37-year-old.
Pirates had parity up front and a solid platform from which to work.
It had early momentum with Warren Kearney, Josh Clark and Hayden Fleury getting the ball over the advantage line.
But a turnover resulted in a try to Zingari halfback Maurice Stone and Chris Bell scored under the posts after a defensive lapse.
Pirates replied through a try to hooker Hamish Boult and a penalty to Craig Sneddon.
But Brew scored from 10m out to give his side a 21-10 lead at the break.
Pirates finished strongly but that was partly down to Brew's absence, as he sat out the last 10 minutes.
Suddenly, Pirates found a bit more space at Montecillo and they scored a couple of consolation tries.
Zingari first five-eighth Thomas Johnson kicked five of his six conversion attempts and had a fine game.
Bell carried the ball strongly, as usual, and lock Reilly Leonard was solid.
Pirates' starting front row of Will Ward, Boult and Jayden Wilcock scrummed well but Kearney was the most effective of the Pirates players.
Kaikorai 47
Green Island 17
Kaikorai overcame a committed Green Island in the last 15 minutes, running in three late tries to secure a convincing win at Bishopscourt.
Green Island got away to the worst possible start in flanker Simon Tupu's 50th game, letting in two tries inside the first five minutes, before rediscovering its mojo and scoring through captain Ricky Hollamby.
From that point, the match ebbed and flowed. Both sides suffered from a high error rate.
With Green Island down to 14 men, Kaikorai took advantage, scoring two late first-half tries, one a penalty try, to gain a four-try bonus point and a 26-10 lead at the break.
Kaikorai's wayward passing and poor discipline let it down in the third quarter, allowing Green Island back into the match through a converted try to Alex Barnsley.
But Kaikorai cleared its bench and its replacement players had an immediate impact, forcing Green Island on to the back foot, as it exploited gaps and dominated territory.
Tony Ensor brought up his 300th point for Kaikorai from a sideline conversion following a Jackson Mitchell try.
