The loose forward trio of Joe Edwards, Woody Martin and try-scorer Tyrone Kemp had strong games, while the return of lock Josh Lane was most welcome.
Even without Middleton, Border were well-served by try-scorer Kieran Hussey and youngster Tobias Stark, while No 8 Semi Vodosese set up one try and just missed another when he lost his footing on a bust near the line, along with lining Kaierau up for some thumping tackles.
Up front, Border dominated Kaierau's scrum until late in the piece – props Ranato Tikiosolomone and Hamish Mellow driving in to twist the momentum and secure penalties and turnovers, while hooker Ross McDonald scored their opening try and laid on another for second five Craig Clare off a nice offload.
Although they kept the full XV on the field this week, Kaierau giving up 30m for backchat and having a lost ball turn into a penalty for mouthing off will have to be addressed.
However, the anger at least served notice that their fire had returned – and from the 60th minute onwards, Kaierau lifted another notch as their younger players emptied the tank and ran from everywhere, taking quick taps on all their penalties to deny Border the chance to use their set-piece.
Fullback Anthony Sellers, winger Harry Unsworth and centre Dillon Adrole, who had struggled to contain Border's strike weapon Alekesio Vakarorogo, began to find gaps, while halfback Caleb Grey got his ball carriers launching as part of an outstanding match.
After a succession of passes set up a corner try to veteran reserve winger Karl Pascoe, Kaierau got straight back down with 90 seconds left and a penalty in front was slotted by Herewini to give his side the win.
"The urgency – we talked a lot about it earlier in the week, it's nice to see a bit more on there," said co-coach Tony McBride, who along with Te Ahu Teki picked up their first win in charge.
"Still learning the patterns but, when we stuck to them, we created some problems, although still a lot of work-ons in terms of decision-making.
"They were up for it today – we talked about getting excited on defence, getting excited on attack and playing as a team as opposed to trying to be individuals scoring.
"It was good to see they actually played for each other again and dug in deep when Border came out in the second half and scored first, instead of folding."
McBride agreed Lane added a lot, while partner Matt Ashworth worked a couple of smart lineout plays with hooker Kohlt Coveny in a solid return to form.
"I feel a bit bad not bringing young Mason [Johnson] on, he's a good footballer, but I didn't want to bring him into that environment when the other two locks were doing their job.
"Stuart Brosnahan made a big impact again coming off the bench. Tyrone [Kemp] had worked hard in the first half with Woody [Martin], so our loosies have really improved in the last two games, and that's a positive for us."
You would have to go back over a decade for the last time Border lost three straight games, although, with two bonus points lifting them into second place at least for the moment, and a much more familiar-looking performance, coach Cole Baldwin was seeing the positives.
"I thought the boys played really well, to be honest, to start off with.
"That last 20 minutes, we just didn't quite get that right. We just needed to play down the other end of the field.
"We couldn't do that and just started giving away penalty after penalty, brought them back into the game, and they got past us right at the end."
Middleton is currently working through a rib injury, one of several players still trying to recover fitness, with the Queen's Birthday Weekend break offering some more recovery time.
"[Middleton's] not quite right, just toughing it out. Luckily we had Kieran Hussey there as well, you don't lose too much," said Baldwin.
"We've had a good week, this week. Thought we had everything pretty much ironed out, but it was the discipline at the end that really hurt us, so hopefully we learn from that."
Kaierau 27 (T Pulemagata, W Martin, T Kemp, K Pascoe tries; B Herewini pen, 2 con) bt Border 24 (R McDonald, K Hussey, C Clare, T Symes tries; Clare 2 con). HT: 19-12.
