Portsmouth are 80 minutes away from a maiden Twickenham appearance after beating Chelmsford 21-14 in the RFU Senior Vase.
The Norway Road club were crowned south-east champions and will now host Honition in the national semi-final on Easter Saturday.
The right to play at the famous stadium awaits the winners.
Neil McRoberts felt Portsmouth’s victory was based on guts and determination.
And the senior coach hailed the desire his troops displayed against Chelmsford.
‘Both teams had to contend with the difficult playing conditions,' said McRoberts.
‘We had to dig deep and play intelligent, appropriate rugby to get the better of very good opponents.
‘It involved a lot of ball carrying, hard work and great physicality.
‘Defensively we got up off the line and did it on the front foot.
‘The players were hungry to make their tackles and made them stick.
‘It was a victory built on our sound defence. Then when our opportunities came along we took them.’
With the strong wind behind them, Portsmouth opened up a 14-0 half-time lead.
The opening 20 minutes were closely fought as both teams looked to impose themselves.
It wasn't until midway through the period that Portsmouth were able to break the deadlock.
A penalty was kicked to the corner and from the resulting line-out the forwards piled over for a try.
Cam Duffus landed the difficult conversion from a difficult position.
The hosts had to show their defensive capabilities as the Essex side looked for a quick response.
Portsmouth's second score came when a penalty try was awarded for a high tackle on Alex Duffus as he sped for the line.
Just before the interval home-winger Noah Cannon pulled off a fantastic try-saving tackle.
The Chelmsford centre was over the line but Cannon turned him on his back and prevent the ball being grounded.
The visitors reduced the deficit with a converted try after the restart.
The next score was crucial – and it was Portsmouth who grabbed it.
A solid scrum provided a good ball and Cannon was there to finish off a three-quarter move.
Duffus again added the extra points in the difficult wind.
The home side had a let off when their opponents knocked on over the try line.
And with eleven minutes left Portsmouth saw their lead cut to seven points, which set up a tense finale.
But Will Brock stole a couple of opposition line-out balls to keep his side in control and see the game out.
McRoberts is excited by the prospect of further cup glory and feels his troops can etch themselves into the club’s history.
He added: ‘We have a fantastic opportunity and great motivation between now and the end of the season.
‘The players have a chance to write themselves into the history books by reaching the national final.’