Also immediately, the visitors were back on attack through their towering centre Kara Adrole, who just palmed her tackler away twice to set up speedy winger Paris Munro, who produced a classic in-and-away to beat three cover defenders and score.
King Country earned a succession of penalties and utilised their big ball-runners, as No8 Uleah Foua eventually dragged two tacklers over the line for 10-5.
But trying to clear their 22m after the restart, they coughed it up and Adrole ran wide and around the cover to dash back to the posts, Tamati converting.
Whanganui put a stamp on the game by halftime when they attacked from a 5m scrum, and although the ball was ripped loose, hooker Waimarama Sinai snatched it to dive over, with flanker Samara Pah-Long adding the extras for 24-5.
Now with the wind, Whanganui started the second half as they finished the first, setting up inside King Country's territory so when they lost it, reserve Kaya Brooks fed Munro to palm off the last defender and score, reserve Cienna Newland converting.
More penalties conceded, however, meant King Country got close enough to spread to the corner and have fullback Hana Kapua just get it down at the flag.
Yet again, they would drop it in their own 22m, and no-one was going to stop Adrole that close to the line, although two tried in vain.
Safe at 36-10 with about 15 minutes left, Whanganui made use of their deep bench, but again penalties were a problem, as King Country finished strongly with two tries.
Their lock dotted down on from a wide run, and then after some good lead-up work from second-five Mila Arnold, their first-five found the gap to run off under the posts with four minutes left.
But the home side had an enemy in the clock and some resolute Whanganui tackling to stop the getting any closer.
Whanganui 36 (K Adrole 2, P Munro 2, T Bogileka, W Sinai tries; R Tamati con, S Pah-Long con, C Newland con) bt King Country 20 (U Floua, H Kapua, No4, No 10 tries). HT: 24-5.
Happenings
Under 16
It was a tough Wednesday afternoon for the AGC Training Whanganui Under 16's against Horowhenua-Kapiti U16 at Spriggens Park. The visitors scored four tries, converting the first, before Whanganui had the final say with a try for 22-5.
Māori under 18
There is an open training muster on Thursday for players interested in being in the Whanganui Māori U18 side to play a game of three halves with Taranaki and Manawatu on October 23. Meet 5.30pm at Cullinane College.
NZ Māori reps
Whanganui's Konradd Newland took the field for NZ Māori Under 18 against Wellington Māori U18 recently.
Wellington included expat Logan Kingi in their lineup. In Girls rugby, Whanganui's Riana Tamati has been called into the NZ Māori Under 18's, heading to Rotorua to prepare to play Waikato Under 20.
Tuimauga
Former Steelform Whanganui and current Manawatu Turbos prop Tietie Tuimauga has been released from his NPC contract to join Irish club Connacht.
The 28-year-old made his debut for Manu Samoa this season.
Connacht is the home club of Tuimauga's former Border and Whanganui teammate Gavin Thornbury.
