A similar pattern continued in the second spell as Central asserted dominance in possession and chances came and went before the home side made it 2-0 17 minutes from time as James Hoyt finished off a quick counter attack with a simple tap in.
Central United coach Jose Figueria applauded his side for an approach which was easy on the eye and produced the desired result.
"I thought we were excellent today," Figueria said, "it was probably important that we got that first goal when we were dominating. I thought it was a real professional, organised and clinical performance, exactly what we wanted."
The five-time winners used the ball well, moving it quickly, making Napier work hard to maintain their defensive shape in front of Underhill, something Figueria says is a product of the players at his disposal -who are involved in a competition which means a lot to the club and the local community.
"We've got the players who can play that way. My job has been just to encourage them to do it. Today we took the chances when we needed to. I thought there were some sublime pieces of football in there and it was great to stand back on the side and watch it."
"The turn out today goes to show how many people hold the Chatham Cup so highly. It seems to invigorate everyone. Cashmere are a great side and they are similar to us and it's going to be a cracking final."
After the final whistle Robertson reflected on a whole-hearted performance from his side which wasn't quite enough to get to the competition showpiece after a wild cup run which included stoppage time, extra-time and penalty shootout victories.
"Obviously we're disappointed to lose," Robertson said.
"Central are a very good side and they put us under pressure for large amounts of the game."
"I'm proud of the boys efforts but I don't think we played as well as we potentially can do. Whether that's our inefficiency or the quality of Central I'm not sure. We're gutted at the moment but we wish Central all the best in the final."
The final of the 91st edition of the ASB Chatham Cup will be played on September 7 with the venue to be determined.