"We won't give up," he said.
"If not anything else, that's the biggest thing I'm proud of. Our game is never over until 90 minutes, until that final whistle goes. Those lads out there will die on the pitch."
The league's leading goal scorer Sam De St Croix had packed his dancing boots for the trip to Whanganui and it was his opening goal for Rangers which sparked the scoring frenzy that followed.
Receiving the ball in the box the striker dazzled the Athletic defence as he shuffled and pirouetted over the ball to create the space for an impressive 7th minute opener.
But it only took four minutes for the home side to find an equaliser.
Logan Hughes took a free kick which pinballed around the box before the ball spewed back out at Hughes' feet and sat up perfectly as he stuck it past a diving Rangers keeper.
Some sloppy Athletic defending handed Rangers the lead back when De St Croix was left unmarked in the box to receive a cross to tap in for his brace.
Two minutes later the visitors stretched out to a 3-1 lead when Can Mustafa headed in from close range, his shot deflecting off the post into the goal.
But this Athletic side have proven all season they are not fazed by falling behind in games and hit straight back in the 31st minute with a goal that almost mirrored their first.
It came again from a Hughes free kick from the same spot as the first.
This time it rebounded out to Ryan Holden who collected it with a soft touch before drilling it into the back of the net.
Athletic almost levelled the game before half time when the ball fell between Athletic's Quinn Mailman and the Rangers keeper who eventually won the race to the ball.
Mailman wouldn't have to wait too long into the second half to take a starring role in the game.
He took the ball at his feet and neatly chipped over the keeper to level the score 3-3 in the 51st minute.
Athletic took confidence from that goal and Mailman earned his side the lead for the first time in the match two minutes later when he latched on to a Jude Hiri cross for his brace.
The home side were now firmly in control of play but their lead lasted just 10 minutes when James Graham got the visitors back into the match.
But for the first time in three games between these two sides this season it was Athletic who found the winner.
It came in the 67th minute when Holden beat the Rangers defence and unselfishly laid the ball off for Ray Hove who beat one defender to find the back of the net to regain the lead.
From there Athletic were able to run down the clock without too much threat of Rangers spoiling the party.
"We spoke at halftime about doing the job," King said.
"We've always wanted to have this as our fortress here and we weren't going to let them mug us off on our own home turf."
One concern may have been a couple of soft goals Athletic handed Rangers.
"Goals galore, I mean, it must have been great to watch from the outside - plenty of entertainment.
"But I was a bit disappointed we threw away the lead we got.
"We always give ourselves lots to do and I saw that goal go in early and I thought 'here we go again'.
"At the end of the day we got that revenge that we wanted."
The win keeps Athletic in third but they have closed the gap on Rangers in second to just three points with matches against teams further down the table to come in the next few weeks.
"I don't like calling them lower table teams because there are some pretty good teams in the league and I don't like underestimating anyone.
"But if we can maintain that attitude and those results then I think we'll be at the right end of the table come the end of the season."
Athletic travel to Palmerston North for the next two weeks to take on bottom of the table Massey Men's 1sts and second to bottom Red Sox Manawatu.