They have punched above their weight in every round, reaching the quarter-final with a thrilling 13-9 victory at Four South West outfit, Glyncorrwg.
Amman United of Four West were the next visitors and this tie was even more tense with Glyncoch edging through 18-16 to set up a semi-final against another Four East side in Talywain.
The Six Central side won through to the Millennium Stadium after a 24-21 victory with three penalties and a conversion from outside half Lee Goddard proving decisive.
"We've been building for the last few seasons and were unbeaten two years ago," said Glyncoch coach David Allen.
"We're unbeaten again this season and hope we can go all the way. We've beaten six Division Four teams this season and they have all been top teams which gives us a lot of confidence. Hopefully we can keep it going. With Ponty here , we're hoping to have very good support."
Division Four East side New Tredegar have kept their best form for the cup, and after two walkovers in the early rounds they defeated Abercarn 19-16 and Abertysswg 9-0. They then travelled to Hafodyrynys in round five where it needed a Ricky Hawkins try and two Craig Thomas penalties to edge through 11-10 against the Five East side.
The quarter-final paired them with Four South West side Resolven but three tries helped the Newts to a 22-17 victory and a meeting with Tycroes in the semi-final. Tycroes have had a good league season finishing in second spot but New Tredegar earned their visit to the Millennium Stadium with a 38-31 success.