When player/coach Cam Goodhue crashed over the tryline close to the posts, Kamo looked odds on to take the lead, but thanks to some quick-thinking by Western Sharks fullback Josiah Povey, the conversion was charged down and the score was locked at 15 all.
With about 7 minutes to go, Kamo's Nikau Graham stepped up and landed a tough penalty kick from 40 metres out on the angle to secure the win.
"It was a good result in the end because [the Western Sharks] were all over us in the first half," Goodhue said.
The Kamo coach credited his flanking partner Berridge for waking the team up at halftime and convincing the players to make their tackles.
"We knew we'd get chances because the mindset changed in that second half, we just went back to what we knew and made sure we did our jobs."
Western Sharks coach Brendan Nathan said the home side took the advantage in the second half after his side was disallowed two tries.
"We can cry as much as we want about the referee's decisions but they happen," he said.
"Kamo have got a really resilient squad and they are highly experienced in the latter stages of the game."
Despite the loss, Nathan was pleased to see his front pack overpower a Kamo forwards unit which contained a number of Northland representatives.
"Kamo is always strong in that area but we worked on our scrumming and lineouts all week and we were the stronger than them in that department I think."
In the round's other games, Waipū beat Mid Northern, 45-19, Hikurangi beat Kerikeri, 27-17, Old Boys Marist beat Otamatea, 46-5 and Wellsford beat Hora Hora 38-10.