Border went a long way to securing their Top 6 spot after a real arm wrestle with neighbours Counties, who will be a little nervous after their 13-7 loss in Waverley.
The visitors were leading 7-5 at halftime, but Border scored the only points of the second half to secure a 5-7 point gap on the teams currently on the bubble at fifth to seventh place.
Taihape kept their mathematical hopes alive after picking up the maximum points on their away trip to Spriggens Park, comfortably beating Marist Buffalo's 44-17.
Kaierau's own mathematical chance at the Top 6 was eliminated by a bottom-of-the-table Ruapehu, who picked up their first win of the season with a 22-12 comeback victory in Ohakune.
In light rain, Ruapehu gave up a Kaierau try in the first five minutes, but got the equaliser ten minutes before the break.
Kaierau's seven pointer after halftime took them clear again, holding onto their advantage despite Ruapehu's second try for 12-10.
However, the home side didn't give up and worked their way to the tryline with five minutes remaining, with reserve Matthew Dowman forcing his way through tackles near the posts for 17-12.
Kaierau were desperate for come back in the dying moments, but instead Ruapehu's Taina Wallace dashed away for his second try.
With Premier rugby on their gap week between the first and second rounds, Ruapehu's Seniors were grateful some of the club's veterans as well as retired players came to help them practice during the week.
Results, May 12
Senior Championship, Round 9.
At Spriggens Park: Taihape bt Buffalo's 44-17. HT: 25-7.
At Waverley: Border bt Counties 13-7. HT: 7-5 Counties.
At Hunterville (Stihl Shop Wanganui Challenge Shield): Kelso Hunterville bt Speirs Food Marton 32-9. HT: 17-9.
At Taihape: Utiku OB bt Seales Winslow Pirates 24-19. HT: 19-13.
At Ohakune: Ruapehu bt Kaierau 22-12. HT: 5-5.
Bye: Celtic.