The Bees completed a perfect campaign by adding the United Counties League’s Premier Division Champions Cup to their Premier Division South title and the Hinchingbrooke Cup.
The unique treble was sealed thanks to a 4-0 success over UCL Premier Division North champions Long Eaton United at the Harborough Town Community Ground last weekend.
And manager Austin conceded it rounded off a season, which delivered more than anyone could have hoped for.
“It’s been an unbelievable season, we have worked really, really hard,” the Bees boss said.
“Did we think we would be sitting at the end of it with 100-plus points, as league champions, Hinchingbrooke Cup winners and champions of champions? Probably not.
“You couldn’t have asked for a better season and I doubt it will ever be repeated again. You could retire off the back of it!
“From my own point of view, it’s not really sunk in just what we have managed to achieve.
“I think I will only realise the extent of it when I look back in a few years and think about what an amazing time it was.
“I have to give the players so much credit. We have some outstanding boys in there and people I didn’t know about until I came to Harborough like Josh Walsh, Freddie Robinson and Rhys Kelly.
“I think we signed players at the right time to give us that extra kick and I think that’s where we had the edge over Hinckley. When we needed to recruit, we did. When they needed to, they stayed loyal to their squad. We needed that kick to spur us on.”
Goals from Nat Ansu, Dodzi Agbenu, Kelly and Sam Hollis gave Harborough their third piece of silverware last Saturday as they saw off their counterparts from the North section.
“There was a lot of talk about the North and South divisions about which was stronger,” Austin added.
“And I say it with all due respect but we beat the top team in there 4-0.
“They had players missing but so did we, we had five missing. It was the same for both teams.”