And they achieved that thanks to tries from wing Matthew Roberts and scrum half JB Bruziller and a conversion and penalty from Matthew Tatchell.
The victory leaves the South two points clear of a North side who travel to Ruthin on Sunday lunchtime knowing that nothing less than a bonus point win will be good enough to make sure of their place in next month's final at St Helens.
The South have one game remaining - at Narberth against the Scarlets next week. Victory there will assure them of a place in the final, whilst a win for the Scarlets will leave them needing a win, of any sort, over the Dragons in their final game.
That game was due to be played at Tredegar last night, but was postponed due to an unplayable surface at The Recreation Ground.
Tonight, the Dragons and Scarlets will do battle at Under 18s, again at Tredegar.