They sealed the deal in their final game in the Borders on Saturday watched by a huge travelling support.
But it wasn’t all plain sailing as their hosts, St Boswell’s, were fired up to try and snatch promotion for themselves.
However, the Dumfries defence, who have conceded fewer points than any team in the National or Premier leagues, was not going to let that happen.
Saints’ had the first three points on the board thanks to a penalty kick by John Carlisle.
Boswell’s responded with a try after several five metre scrums, but the conversion was missed.
Sam Hiddleston crashed through to score under the posts for the visitors and a John Carlisle conversion took them into half time with a 5:10 scoreline.
The second half was a Saints masterclass in how to keep possession and build phases.
Jack Steele scored under the posts and a conversion saw Saints go 5:17 up.
Meanwhile, the St Boswell’s squad was becoming depleted as player after player left the field injured. Dumfries used the space to send Andrew Whiteford up the line for the final try, John Carlisle converted taking the score to 5:24.
The rest of the game had Saints in control of possession and not a lot a worn-out St Boswell’s could do about it.
This was performance that contained some of the best rugby played by a squad of seasoned campaigners that play for each other, play for the club and play to win.
Saints Coach Ed Barnes said: “In the first half we couldn’t quite get our kicking game going and handed so much possession to St Boswells through our penalty count. In the second half ball retention, attacking structures, defence and attitude were top drawer with not one man backing down physically.”
But he added: “Ultimately, it was our ability to adapt our game planning, coupled by superior fitness levels, desire and determination that sealed it for us.
“Congratulations to the entire senior squad on an outstanding campaign.”