The Citizens beat Port Talbot 2-1 despite playing for all but 10 minutes with 10-men after the early dismissal of Michael Walsh for a rash challenge on Lewis Harlin.
But Les Davies fired the visitors in front on 27 minutes and Kyle Wilson added another five minutes later.
Martin Rose did pull one back for the Steelmen just past the half hour when his shot off the crossbar was adjudged to have crossed the line, but there was no addition to the scoring in a scrappy second half.
The New Saints were grateful for an early Christmas present which gifted them only goal of the game after just six minutes at Carmarthen Town.
Goalkeeper Rhys Wilson failed to deal with a right-wing cross from Craig Jones and his punch fell to Alex Darlington, who took one touch before driving the ball into the net from six yards.
Aeron Edwards came close to increasing the lead midway through the first-half when he curled a shot against the post with Wilson beaten.
Celebrating his 150th consecutive game for the club, TNS keeper Paul Harrison got down well to block at the feet of Nick Harrhy on the hour but, with the atrocious conditions deteriorating rapidly, the Saints failed to turn their increasing domination into goals.
Airbus UK Broughton cruised to a 3-1 win at Newtown's Latham Park.
Goals from Ian Sheridan and Mike Hayes put the Wingmakers well in control midway through the first half and sub Mark Allen added the third against one of his former clubs on 52 minutes.
Zac Evans notched a late consolation penalty for the Robins.