Two goals inside eight minutes from Matty Williams took his season's goal tally to 14, but it took the Saints almost an hour to break down a resolute and well-organised visiting defence.
Clearly happy to settle for a draw to take their unbeaten run to 13 games, the Reds maintained a high backline to frustrate the TNS attack, while rarely threatening a makeshift home rearguard missing Phil Baker and Chris Marriott, both injured in Saturday's mud-slog at Rhyl.
Jamie Wood brought a good save from keeper Ashley Morris on the quarter-hour and Williams collided with the goalpost as his follow-up attempt was blocked.
Saints' keeper Paul Harrison got down well to an Andy Legg free-kick, while the threatening Jason Bowen fired wide.
The breakthrough arrived during a spell of pressure on 56 minutes following a Matthew Berkeley cross when Aeron Edwards was pushed by Martyn Giles as he was about to score.
Despite denying a clear goal scoring opportunity, the defender escaped with a caution, but Williams extracted full revenge by blasting the resulting penalty into the roof of the net.
And, seven minutes later, Williams forced the ball home from close range after the fourth corner in succession.
Legg fired an effort wide for the visitors from a Rhys Griffiths flick, but the Saints were rarely troubled as they banked three precious points, a highly satisfactory performance in view of the key players on the sidelines.
Photo: Matty Williams beats Llanelli keeper Ashley Morris for the second goal.