Llanelli lost captain and lock Adam Powell after 23 minutes, but Aberavon had earlier seen their Academy full back Joe Gage depart, also with injury, though his replacement Jonny Phillips tore in for a try on his first touch and third in successive matches.
No 8 Chris Davies not only took the skipper’s job, but gave an outstanding display in the Wizards’ back row, while Llanelli’s Jordan Williams, out of place as left wing, scored twice despite being rarely fed by his centres.
Aberavon’s head coach Jason Hyatt said: “This was a splendid display and I am very proud of this squad.”
Kevin George, the former Aberavon scrum half and centre and now Llanelli’s director of rugby, said: “Our play became far too loose and losing Adam Powell was a huge blow to us.”
Llanelli lost their lock forward Maselino Paulino to a yellow card before Phillips scored and James Garland converted but the returning Paulino went over with Josh Lewis converting to level it.
Then centre Joe Thomas eluded two defenders to score only for Jordan Williams to race over and make it 14-14 at the interval.
After 46 minutes a superb run by Jay Baker saw him beat man after man before hooker Gareth Harvey scored in the corner and then an amazing length-of-the-field move saw Baker tear Llanelli apart and Stefan Andrews crossed for Garland to convert.
Aberavon added further tries by replacement Sam Williams and Garland with first Garland and then Phillips converting before Jordan Williams scored his second and converted right on time.
Referee Tim Spurrier handled his first Premiership match and was well up with a fast game at all times.
Scorers: Aberavon – Tries – J Phillips, J Thomas, G Harvey, S Andrews, S Williams, J Garland. Cons – Garland (3), J Phillips.
Llanelli – Tries – J Williams 2, M Paulino. Cons – J Lewis, J Williams.
