Veteran back Josiah Bogileka slotted two conversions and a penalty.
Ngamatapouri could not quite crack the bonus point after scoring three tries, which included a double from winger Joeli Rauca to follow-up his hat-trick in the win over Ruapehu.
Over at Memorial Park, Byford's Readimix Taihape had a comprehensive 32-8 win over Wanganui Car Centre Kaierau, cementing them in the other home semifinal spot.
Taihape have been scalped at home the past two seasons by Kaierau, but right now are running hot in the followup to their flogging of Marist, while the visitors have gone from winning the Paul Mitchell Cup as first round leaders last year, to slipping back to third after back-to-back defeats.
The host led 17-8 at halftime, with Kaierau getting their points through winger Stu Brosnahan scoring in consecutive games, plus a penalty from second-five Ethan Robinson.
But Taihape continued to pull away, moving to 25-8 and then scoring again before fulltime to pick up the bonus point.
No 8 Ben Whale added another try to his tally, while outside backs Tyler Rogers-Holden and Tyrese Payne also dotted down.
No doubt relishing his five points was midfielder Tim Goodwin, who had left Kaierau last year in search of a more prominent spot in a Premier lineup and continues to commute to Taihape for training and matches.
In Senior rugby, Speirs Food Marton lifted to a big second half against Marist Buffalo's at Spriggens, coming from 10-5 behind for a 31-16 upset win.
Up at Rochfort Park, it was a real grind for McCrea Scanning Counties, but two second-half penalties were enough to see them past Ruapehu 16-12 for a morale-boosting victory, although they stay bottom of the table at this stage.
At the top end, Kelso Hunterville and their leading rival and defending champions Harvey Round Motors Pirates both picked up impressive wins at home.
Hunterville ran away with it in the second half to hammer Border 69-14, but Ratana really made a statement by knocking Black Bull Liquor Pirates back out of the Top 4 again with a 59-7 win at the Pa, which included a point-a-minute in the first half.
Ali Arc Logistics-DNA Kennels Marist Celtic made their first defence of the Stihl Shop Wanganui Challenge Shield with a fairly comfortable 23-5 away win over Utiku Old Boys, while on the opposite field at Memorial Park, Gemini Pepper Construction Kaierau held off Bennett's Taihape in a 27-21 thriller.
Results, May 22
Tasman Tanning Premier, Week 5
Dave Hoskin Carriers Marist 32 (George Forster 2, Jack Yarrall, Jamie Robertson, Luke Foster tries; Jo Bogileka pen, 2 con) bt Settlers Honey Ngamatapouri 17 (Joeli Rauca 2, Te Rau Wirihana tries; Brook Tremayne con). HT: 20-10.
Byford's Readimix Taihape 32 (Tyler Rogers-Holden, Ben Whale, Tim Goodwin, Tyrese Payne tries; Dane Whale 2 pen, 3 con) bt Wanganui Car Centre Kaierau 8 (Stu Brosnahan try, Ethan Robinson pen). HT: 17-8.
Grand Hotel Challenge Shield – Waverley Harvesting Border 41 (Vereniki Tikoisolomone 3, Tyrone Albert, Angus Middleton, Semi Vodosese, James McDonald tries; Jack Lupton 2 con, Craig Clare con) bt McCarthy Transport Ruapehu 10 (Morvin Trow try; Tuhirangi Akapita pen, con). HT: 24-10.
Senior Championship, Week 6
At Spriggens Park: Speirs Food Marton bt Marist Buffalo's 31-16. HT: 10-5 Buffalo's,
At Ratana Pa: Harvey Round Motors Ratana bt Black Bull Liquor Pirates 59-7. HT: 40-0.
At Hunterville: Kelso Hunterville bt Border 69-14. HT: 25-7.
At Memorial Park: Gemini Pepper Construction Kaierau bt Bennett's Taihape 27-21. HT: 10-5 Kaierau.
At Memorial Pak (Stihl Shop Wanganui Challenge Shield): Ali Arc Logistics-DNA Kennels Marist Celtic bt Utiku OB 23-5. HT: 8-0.
At Rochfort Park: McCrea Scanning Counties bt Ruapehu 16-12. HT: 10-7.
Round the grounds
METRO: The St Johns Whanganui Metro side sits top of the table after the first round of the MRU Colts competition following a 33-0 shutout of Freyberg Old Boys at Colquhoun Park on Saturday. It sets up a big game to start the second round in Whanganui against the only team to beat them in Feilding Old Boys.
COLLEGIATE: It's been a mixed start for the Whanganui Collegiate 1st XV in the Central North Island competition. Collegiate kicked off with an impressive 30-7 home win over St John's Hamilton on Wednesday, but suffered a 28-15 loss away to co-defending champions St Peter's Cambridge on Saturday.
PREMIER 2: The Whanganui High School and Cullinane College 1st XVs began their MRU Premier 2 grade a day earlier than the rest on Friday, with WHS winning the derby 24-12 after leading 12-7 at halftime. In Premier 3a, Whanganui Collegiate 2nd XV beat St Peter's College 41-19.
