Witcombe said his team looked like a bunch of young boys enjoying themselves, and delighting the locals.
"It's just great that our little rugby team can inspire the region like that," Witcombe said with a smile.
"It's part of what we're trying to do with our picking, which, in turn, will get the support.
"That was a performance to be proud of.
"We knew it'd be a hard game and we had to go out there and grab that game early.
"They'd come off two good wins - against Canterbury and Hawke's Bay - and Harbour are always a tough team for us to play. The boys should be proud of that."
In terms of where such an impressive performance came from, Witcombe felt it was something they'd worked towards.
Witcombe and assistant coach George Konia have tried to empower the players with the belief they can have a crack when they see an opportunity - of which the Taniwha did plenty of on Friday night.
"Part of what George and I talked about at the start of the year is that they already are good players, but we want them to express themselves.
"If they see something in front of them they can go for it but there's a structure there.
"They kept to the game plan [on Friday], although we made it hard for ourselves in the first half and made too many errors."
Enjoying the freedom to express himself more than others was fullback Matt Wright, picking up just the second hat-trick in the ITM Cup this season.
Following up from his brother Ross Wright, who scored the team's first try, Matt showed why he was into his third season with the Taniwha - often proving to be Johnny on the spot.
Witcombe knew Matt would have enjoyed his try-scoring antics, adding he would have been as humble as ever also.
"He's a good little player, [and] when it clicks for him it really clicks. He'd probably say he was on the end of a team performance but he always turns up at the right time."
While the thought of a semifinal spot in two weeks was satisfying for Witcombe, like usual, he said his team would stay grounded and not get ahead of themselves.
"I say it every week, we will enjoy the win and now it's time to move on. If we play like that we can surely go and beat Auckland."
Witcombe invited Northland supporters to get on the road and support the Taniwha at Eden Park on Saturday, saying it's just a couple of hours down the road.
