The Hawks are on the tail of Southern, which reclaimed top spot in the standings with a bonus point win over Alhambra Union.
University A survived a scare against lowly Pirates, Dunedin demolished Green Island and Zingari Richmond fought back from a 15 point deficit to clinch a draw against Kaikorai.
Harbour 27
Taieri 5
Harbour has won its past nine games and has not been beaten since round one.
It is the team to beat, and demonstrated just how far it has come with a comprehensive win over Taieri for the Henderson Memorial at Watson Park.
The last time the two sides met, they fought out a 31-31 draw. But Harbour dominated the return fixture through its impressive forward pack and led 17-5 at the break.
The home side had some discipline issues, though. Reserve James Tomkinson was yellow carded in a first half for an infringement. And an ugly incident in the final quarter of the match saw two players - Harbour's Aleki Morris and Taieri's Karl Stil - yellow carded for their involvement in a scuffle, while Harbour's Ratu Dawai was red carded.
Despite being down to 13 men, Harbour scored when captain Charles Elton crashed over following a scrum close to Taieri's line.
The game's opening points were scored by Hadleigh May. The openside flanker ran 50m to score after a loose pass from Taieri's Willis Scott was scooped up and transferred through several set of hands before May got in the clear.
Lock Sione Misiloi also scored before the break. Fullback Logan Allen converted all three tries and made some wonderful clearing punts.
Charlie O'Connell had a strong game for Taieri and scored the team's only points.
Southern 48
Alhambra Union 3
Southern was too big, too strong and too skilful for Alhambra Union at the North Ground.
While the set pieces were reasonably even, Southern was able to control play as forwards Mika Mafi, Adam Knight and Tim Ferguson got past the advantage line regularly. That set up a wonderful platform for centres Tei Waldon and Nathan Cargo to run amok, bagging two tries apiece.
Whenever Alhambra Union was able to string a few phases together, it would lose the ball in the contact or through some poor passing. The home side did not defend well either, falling off too many soft tackles.
Alhambra Union's best period came in the last 15 minutes of the first half but it trailed 28 3 at the break-
Southern continued to dominate and enjoyed a territory and possession advantage. The win has lifted it a point clear at the top of the table.
Centre Tili Puloka stood out in a losing effort for Alhambra Union. Prop Bevan Bolger gave a good account of himself, while lock Mike Colville nabbed his share of lineout ball.
But it was Southern's day, and Mafi, Knight and Ferguson made too many easy yards.
University A 18
Pirates 11
It was an arm wrestle at the University Oval, as University A overcame a niggling Pirates side.
Pirates appeared destined to struggle, as only seven members of its original 22 were still available to play. Despite the raft of changes, Pirates controlled the game in the first half, through bustling play and good work at the set piece through Hisa Sasagi, Hamish Boult and Craig Millar.
Loose forward Jeff Evans Turner also stood out as Pirates led 5-3 at the break.
University A changed its approach after halftime, regaining control at the set piece and breakdown, allowing dangerous No8 Dillon Hunt and the inside back trio of Kaide Whiting, Fletcher Smith and Shae Tucker some room to move.
Whiting's speed to the ball paid off when he scored to put University A ahead in the 52nd minute, and played a role in winger Gavin Stark scoring his try.
The students grew in confidence but Pirates countered, and although the game turned into a relative stalemate, University A would have been grateful to bank the four points and Pirates a well deserved bonus point.
Zingari Richmond 25
Kaikorai 25
A spirited and largely inexperienced Zingari Richmond side overcame a 22-7 deficit early in the second half to share the spoils and retain the Tom Watkins Memorial trophy at Montecillo.
Already hit by injuries to some key players, Zingari suffered a further setback when it lost a key member of its forward pack, Blair Tweed, in the opening minute of play.
Kaikorai took full advantage and established a 15-0 lead, but the final minutes of the first half belonged to the home side. No8 Tom Cummins bagged the first of his two tries to give the scoreline some respectability at 15-7, as the teams changed ends.
Despite Kaikorai scoring again soon after the break, it was all Zingari for the majority of the second half as it ran in a further three tries to tie the game at 22-22.
Kaikorai had an opportunity to steal the game through a late penalty, only to surrender its chance straight from the kick off.
Thomas Johnson, already with a century of points this season, made no mistake with the shot at goal, to tie the game up and keep the silverware locked up at Montecillo for another 12 months.
Dunedin 52
Green Island 7
If you blinked, you might have missed Dunedin's first two tries.
The Sharks were up 14-0 after five minutes at Miller Park and Green Island was unable to respond.
Debutant winger Cory Rakich scored with his first touch of the ball in premier rugby, ghosting through a gap in the opening 30 seconds, and with a wealth of front foot ball, Dunedin scored seven tries.
Fellow winger Henry Scott and powerful loose forward Matthew Vaai scored two tries each and Greg Dyer and Mark Grieve Dunn also dotted down.
Green Island prop Terry Gough scored a five pointer for Green Island but Dunedin's pack had a firm grip on the Terry Murphy Memorial.
Classy Green Island winger Fapene Popoali'i received a yellow card, which did not help, and his side trailed 25-7 at the break.
Vaai and fellow loose forwards Alex Fitzgerald and Hame Toma were outstanding. Toma was seemingly everywhere.
For Green Island, No8 Jackson Hemopo stood out, as he always does. Blindside flanker Lausei Pritchard had a high work rate while Sam Eriepa was solid in the midfield.
