TNS overcame their Latham Park hoodoo to close the gap on leaders Llanelli to just one point.
However the Saints were once again handed a fright by a Newtown side clinging to the hope of Super 12 qualification.
Newtown’s resistance ended after just 13 minutes, when Tommy Holmes’ left-wing cross fell for Matthew Berkeley who made no mistake from six yards.
Welsh schoolboy international Jamie Breese was full of industry for the home side, and within three minutes his cross was steered wide of the far post by an unmarked Paul Roberts.
Roberts’ miss proved costly as TNS doubled their lead on 31 minutes, with Craig Jones skipping down the right-wing and crossing for former Latham Park favourite Scott Ruscoe to volley home.
Newtown are no push overs this season and despite struggling to create any clear openings, the Robins had their share of possession.
TNS on the other hand were harried and hassled throughout the second-half, with the outstanding Andrew Thomas leading by example and organising the home rearguard to stifle the Saints
However Newtown continued to lack the cutting edge to force a route back into the derby, with Ross Stephens lashing wide from distance, while Paul Roberts was also guilty of poor finishing.
The Robins search for a response came increasingly desperate as time ebbed away, with Neil Mitchell volleying over from 25 yards, while Adam Worton’s low corner caused chaos in the area.
Despite their possession Newtown were almost punished at the death with TNS’ star January window signing Chris Sharp creating space down the left, before picking out Craig Jones, who was somehow denied by a fine reaction save from Dave Roberts.
NEWTOWN: D Roberts, Williams, Hughes (Dawson), Blain (Russell), James, Thomas, Worton, Mitchell, P Roberts (Webb), Stephens, Breese. Subs: T Jones, McFadden
TNS: Harrison, D Holmes, T Holmes, Baker, Evans, Hogan, Ruscoe, Berkeley (Darlington), Sharp, Williams (Seargeant), C Jones. Sub: Wood