But it took the lethargic visitors more than an hour to shake off the effects of their Christmas pudding, by which time the Robins were a goal to the good, Luke Boundford heading into the far corner from a right-wing flag kick.
At that stage of the game their lead was well-deserved - Nicky Rushton had hit a post minutes earlier and referee Brian James ignored two strong penalty claims in the first-half, whileTNS keeper Paul Harrison also saved well to deny Robbie Millington.
But the arrival of subs Scott Ruscoe and Tom Roberts injected some life into the visitors, who levelled when Simon Spender fired home after being set-up by Chris Seargeant.
Roberts then fired home an 18-yarder and an unmarked Craig Jones headed home from Ruscoe's cross to complete a three-goal burst inside seven minutes.
Bala Town secured a top-six spot at the split in a closeley-contested affair at Maes Tegid where, after the hosts had missed a first-half penalty, the only goal of the game arrived nine minutes from time and was credited to Airbus UK Broughton skipper Mark Allen.
Port Talbot are now winless in eight league and cup games after being held to a 2-2 home draw at the GenQuip Stadium by derby rivals Afan Lido.
Jonathan Hood put the visitors in front and scored their equaliser after goals for the Steelmen from Martin Rose and David Brooks.
Aberystwyth gained a much-needed win to leave Carmarthen Town rooted to the foot of the table.
Wyn Thomas drilled a shot from the edge of the area to give the Seasiders a fifth-minute lead and Sion James doubled the advantage with a 30-yard piledriver.
Steffan Williams broke between two home defenders to reduce the deficit just before the break, but Andy Parkinson sealed the Old Gold's fate on 76 minutes, breaking inside from the left before planting a shot into the bottom corner, and another from Kris Nalborski was the icing on the home side's Christmas cake.