It has grown into the most evenly matched rivalry in 2013 Wanganui premier rugby and is likely to play out another chapter come the August semifinals.
But for now Border maintain a bare ascendancy over Pirates after Saturday saw another one-point war of attrition at Dallison Park the boot of Mark Davis proving the difference, 17-16.
It was a game played hard but relatively cleanly after the red-card bonanza at Spriggens Park in April, although moments of Pirates indiscipline proved costly inside the final 10 minutes.
The visitors outscored Border two tries to one through halfback Josh Navitio and first-five Denning Tyrell, but fullback Josh Marwick (two from eight) struggled with his kicks in the South Taranaki breeze.
In contrast, first-five Davis was in deft touch landing four from five including the decisive penalty in the 73rd minute, while setting up Border's try to winger Aaron Vadiga and tackling Pirates' big men around their bootlaces.
"He's a class act, been around the traps and knows how to close the game down," said Border coach Peter Richardson.
Pleased his side had shown the passion to hold out, Richardson acknowledge their problems with loose floating passes when they tried to spread the ball wide, which ruined several promising phases.
"It's a shame because it's where our strengths are, but it got a bit rushed and we panicked.
"Two games, just two points [between us]. It seems to be the way we play."
Disappointed Pirates coach Phillip Morris said: "It was always going to be a game of inches.We had the field position, but didn't carry on and we missed some kicks."
He was pleased his big forwards rocked the Border pack throughout, including taking three scrum feeds off them.
"That's rare. We've just got to keep building on that. It was a much better performance, we've worked hard but we just want the result."
Border were led out by No8 Kane Brisco, celebrating his 100th game, and he wasted no time making it a memorable one with some crunching tackles.
It was a first half in which the lead changed hands with every score, as referee Peter Clarke was quick to come down on hands in the ruck.
Davis opened the account from in front in the sixth minute, before Pirates ground out territory advantage with hooker Junior Tume pulling out some great short passes. His pack opened it up for Navitio to barge over in the far left corner.
Pirates were caught by Clarke again in front of their posts, for Davis to regain Border's lead, before his own team were guilty at ruck time, for Marwick to flip the switch to 8-6 after 22 minutes.
Lasa Ulukuta opened Border up midfield but Pirates could not capitalise.
Davis then stamped his mark with a series of jinking runs to find the gaps spreading the ball out to Vadiga to crash over in the far right corner.
Pirates had a golden chance when Marwick snatched a chip kick and scooted away but the ball was spilled with the line begging.
Border came out firing in the second half and pounded the Pirates line, but haphazard passing handicapped their efforts.
As play moved back and forth between the 22m zones, Pirates tied the scores with a Marwick penalty, although the fullback faltered with his other attempts.
After 63 minutes, they seemed to gain ascendancy when a shallow Border clearance was snaffled up and Tyrell burst free down the touchline, celebrating before he put it down.
However, Davis coolly replied with another penalty three minutes later.
Again, Pirates' big ball runners drove them back downfield but Border's defence held.
Vadiga broke through but was taken out after his chip ahead, and Davis curved a difficult kick inside the left-hand post.
Marwick could not reply with his three-point attempt, and then Clarke reversed a Pirates penalty after one of their forwards trod on a Border player.
Davis trapped Pirates deep and then his tackle shut down their breakout to wrap the game up.
Waverley Harvesting Border 17 (Aaron Vadiga try, Mark Davis 4 pen) bt Integrity Motors Pirates 16 (Josh Navitio, Denning Tyrell tries, Josh Marwick 2 pen). HT: 11-8.