The side needed to win and score a four-try bonus point to get into the top four and, in the end, did it easily to confirm its place in the top four.
It will play top qualifier University next week while Taieri will host Harbour. University won the Gallaway Trophy on Saturday after the completion of the second round.
Kaikorai 48
Harbour 21
Kaikorai did the business and more and left Harbour in its wake.
It scored its fourth try within the first 30 minutes of the match and then snuffed out any hope of a Harbour comeback early in the second half.
Kaikorai showed greater urgency at Watson Park and made the advantage line with ease.
It forwards ran with purpose and strength while the midfield of TJ Ane and Eti Slater made some nice metres.
When winger Matt Jones intercepted a loose Harbour pass and ran 60m to score, Kaikorai had the four-try bonus point and then just had to hang on and win the game.
Harbour had actually opened the scoring with a try to prop Alex Nettleton after three minutes but the visiting side dominated the rest of the half to lead 24-7 at the break.
Logan Allen scored a try early in the second half and there was a flicker of hope Harbour could come back into the game.
But Slater scored his second try and Kaikorai eventually ran away with the match.
The Kaikorai pack hunted as one and prop Sam Wyber, and loose forwards Riley McDowall and Sean Jansen worked hard. Josh Renton threw out some nice passes while Ben Miller grew as the game went on and scored a nice try at the end.
Harbour looked like a side which had little to play for and was a tad directionless at times. Forward Charles Elton and Alan Burling tried hard while Allen showed nice touches but had little room to move.
Taieri 74
Zingari-Richmond 19
Taieri made no race of it at Peter Johnstone Park and shared the points around against Zingari-Richmond.
The colours will not look back at this season with much delight and they once again slipped off tackles the longer the game went on.
Zingari actually led 7-5 early in the game after centre Tevita Nabura scored a nice try but it was very much a false dawn as Taieri pulled away to lead 38-7 after 40 minutes.
The Taieri team moved the ball around well and found space when it needed to as Zingari-Richmond struggled to shut it down.
Taieri fullback Josh Casey made the most of any room he was given and helped himself to three tries. His running game was a constant danger to the opposition and he sniffed out any chance.
Highlanders prop Guy Millar scored two tries as he got around the field while openside flanker Josh Brown enjoyed the open territory.
Highlanders back Tevita Nabura scored the opening try for Zingari-Richmond but then was yellow-carded for pulling back a player and preventing a try. A penalty try was awarded.
Taieri centre Matt Whaanga made a powerful 40m run to score a try and was generally lively in everything he did.
Zingari-Richmond No8 Chris Bell, setting a record of 243 premier club appearances for one club, tried his hardest but it has been a tough year for the side. It won the first game against Harbour and then did not win another game all season.
Alhambra-Union 27
Southern 26
Alhambra-Union finally put things together and had that slice of luck to beat Southern 27-26 at the North Ground.The home team had been in most games but before Saturday had registered just three wins. It had come up just short in many games and tended to lose key moments in the 80 minutes.
On Saturday, it made the most of the opportunities which came along and stayed ahead.
It led 15-12 at the break and was just one point ahead with time all but up. It received a penalty right out in front of the posts but, much to the horror of its supporters, decided to run the ball.
The ball was turned over but Southern could not take advantage and the combined side hung on for the win.
Alhambra-Union played an all-inclusive, expansive game which Southern tried to match for much of the game when perhaps the visiting team should have kept the ball more in the forwards. Southern did not help itself by having lock Pari Pari Parkinson yellow-carded for interfering in the lineout and second five-eighth Tama Apineru also cooled his heels for a tip tackle.
Alhambra-Union halfback Legin Felix-Hotham had a fine game and was rewarded with two tries. No8 Connor van Turnout played well and the Alhambra-Union backline ran hard.
Kyle Harris put in another good shift for Southern as did big prop Mike Mata’afa. Left winger Tom Yarrall scored two tries for Southern and was tidy in everything he did.
Dunedin 36
Green Island 22
Dunedin played with a strong breeze in the first spell but led by only nine at the break and looked to be in trouble.The home side defended tigerishly in the first spell and kept Dunedin to three tries while scoring two of its own.
Four of the tries came from forward drives as the two packs went at it with a real will.
Dunedin certainly looked sharper in the backs and scored a try of real class late in the spell when fullback Josh McKay found some space and hit winger Cam Hay with a wide pass who chipped over and regathered to score under the bar.
In the second spell, Dunedin found big holes in the defence through its powerful ball runners in lock Mark Grieve Dunn and No8 Morgan Reedy.
Hay and Rory Ward capitalised and dashed away for tries to put the game beyond doubt.
Green Island’s forwards never gave up and earned a deserved bonus point by scoring two more tries from forward drives close to the line.
For Dunedin, Grieve Dunn was outstanding, eating up the metres. Reedy and blazer game player Jamie Mowat supported well and tackled with real intensity. Hay was the best back on the paddock and McKay was dangerous with his vision and pace.
The Green Island pack never took a backward step and lock Woody Kirkwood was probably its best. Loose forwards Brett Kingsbury and Josh Hayward had their moments.
Round 18
The scores
Alhambra-Union 27 (Legin Felix-Hotham 2, John Tapueluelu 2, Ben Webby tries; Brady Kingan con) Southern 26 (Tom Yarrall 2, Jermayne Maika, Callum Brown tries; Mackenzie Haugh 3 con) Halftime: 15-12 A-Union
Taieri 74 (Josh Casey 3, Guy Millar 2, Vinnie O’Connell, Brodie Hume, Brodie Flannery, Shannon Young, Matt Whaanga, Glen Beadle tries; penalty try; Casey 6 con) Zingari-Richmond 19 (Tevita Nabura 2, Karl Still tries, Sasha Bachurin 2 con) Halftime: 38-7
Kaikorai 48 (Matt Jones 2, Eti Slater 2, Sam Wyber, Riley McDowall, TJ Ane, Ben Miller tries; Miller 4 con) Harbour 21 (Alex Nettleton, Logan Allen, Ewan Brumwell tries; Allen 3 con) Halftime: 24-7
Dunedin 36 (Mark Grieve Dunn 2, Cam Hays 2, Morgan Reedy, Rory Ward tries; Cormack Fox 3 con) Green Island 22 (Josh Hayward, Jared Williams, Jake Fowler, Devlin Stanley tries; Alex Barnsley con) Halftime: 19-10 Dunedin