After making a host of new signings earlier in the week, Aberavon's fresh faces guided the team home. And former Carmarthen Quins centre Rheon James, making his Aberavon debut after joining from Cornish Pirates, denied Swansea a losing bonus point with a try late on.
With the game played out in driving rain, Aberavon were on top for most of the encounter.
"We were nervous and missed two good chances for tries," said Aberavon head coach Jason Hyatt.
"To their credit, Swansea never turned it in but I thought we deserved the points."
In such dour conditions, the game was always going to be won or lost up front and with Gavin Ronan, Ian Moore - on his 300th appearance in red and black, and Ieuan Davies all fronting up to the Swansea pack, the Wizards slowly got on top.
Wing Richard Carter opened the scoring by diving over in the corner but two penalties from Cameron Clement put Swansea ahead by a point.
A Ceiron Thomas three-pointer put the Wizards back in front and it stayed that way going into the final 10 minutes.
Swansea were chasing the game but they could not break through with Jamie Davies kicking a penalty and converting James' late effort.
In the other Premiership fixture to take place, Bedwas claimed an impressive home win over inform Cross Keys.
Steve Law's men defied a wet and windy Bridge Field to run out 22-12 winners with Simon Grainger, Richard Wilkes and Rory Budina crossing for tries.
Keys were indebted to Dorian Jones for keeping them in the game but his three penalties and a drop goal were not enough.
With the fierce wind at their backs in the first half, Bedwas started on the front foot and put the first points on the board via Richard Powell's boot.
The home side kept up the pressure and from a five metre scrum, Grainger was driven over the line with Powell adding the extra two.
Jones pulled a penalty back for Keys but with the weather deteriorating, hooker Wilkes was driven over for the home side's second try. Powell missed with his conversion and as the torrential rain hammered down, there was no further first half score.
With conditions now in their favour, two more Jones penalties gave Keys hope. But Bedwas were not to be denied victory, Budina showing his trademark pace off the mark to dot down from a cleverly placed kick. Powell made the wind look negligible with his expert conversion.
Jones added a smart late drop goal but Bedwas dug in and were in no mood to relinquish the victory.
Principality Premiership results:
Aberavon 18-6 Swansea
Bedwas 22-12 Cross Keys