The Welsh All Blacks overcame a 30-minutes delay at the start of the second half as the generator ran out of diesel causing a floodlight failure and the home side themselves ran out of energy against an unrelenting wave of Neath forwards surges.
The Gnoll forwards created two pushover scores as they dominated the scrummage while locks Gavin Evans and Lee Bassett secured a plentiful supply of possession at the line-outs. The fact that the visitors failed to convert possession into points had more to do with some generous refereeing of the offside rule as the visitors found limited space in midfield.
Number eight Gareth Williams opened the scoring rounding off a flowing Ponty attack with an unconverted try, while Neath replied almost immediately as scrum half Gareth James collected his first try of the evening benefitting from a superb scrummage lead by the Neath front row trio of Paul James, Adam Matthews and Adam Jones.
Fly half Mike Thomas restored the home sides lead only for Dylan Pugh to level the scores midway through the first half. Any signs of a repeat half century of points performance as shown against Swansea in the previous round were not visible at Sardis Road even before the temporary gloom as Neath fell behind to a 15pts to 8 after Thomas scored a converted try at the posts.
After a hurried visit to the local garage and lights restored, Neath firstly levelled the scores after prop Paul James capitalised fully on the sinbinning of Thomas to crash over for a try.
While Ponty had their moments, the visitors took the lead for the first time in the match as scrum half James collected his second try at the base of another rapidly advancing Neath scrum. Pugh, growing in statue as the season progresses, added both conversions.
Left wing James Watkins seized on a Neath defensive error to score wide out and while the try went unconverted with Thomas missing all his second half attempts at goal, Pugh settled the visitors nerves with his second penalty of the evening to set up a final against the winners of friday evenings clash between Cardiff and Llanelli.
Wales Head Coach Rob Howley talks to WRU TV's Sebastian Barrett about the 36-man squad he has just named for the forthcoming Under Armour series, which includes two uncapped players, Ospreys duo Sam Davies and Rory Thornton.
Head coach Rowland Phillips is deligthed he can now call BT Sport Cardiff Arms Park home for his Wales Women's side, who launch their international season next month with games against Scotland and UK Armed Forces in the heart of the capital city.
Wales Sevens star Sam Cross has put his home town club of Brynmawr on the map after winning a silver medal at the Rio Olympics with Team GB. His club have now honoured him by naming their players bar after him, as WRU TV discovered at the official launch, recently.
One of the newest members of the Principality Premiership, Bargoed admit it's proving to be a steep learning curve at the highest level, but are determined to become a force to be reckoned with. WRU TV visited the club last weekend when they took on Llanelli.
Table-topping Aberavon travel to north Wales to tackle RGC 1404 as both teams defend unbeaten starts to the season in the Principality Premiership. WRU TV's Graeme Gillespie visited the Wizards to see how their preparations were going for the game of the weekend.
The Half a Game initiative is currently sweeping across Wales and proving a major success. The scheme aims to give every young player at least half a game every weekend. WRU TV recently visited a festival in Narberth where clubs have fully embraced the initiative.
Both Bargoed and Swansea were seeking their first win of the Principality Premiership season this afternoon. It proved a fruitful day for the hosts - not only did they win, but Bargoed claimed a try bonus point.
Cardiff managed to keep their unbeaten record at home intact, but only just as Bridgend made them work extremely hard before the Blue and Blacks secured a hard fought Principality Premiership win at the BT Sport Arms Park last night.
Former Wales back row Andy Powell gives a guided tour of The Wern, home of Merthyr RFC, who are determined to prove a lot of people wrong and make their mark in their first season in the Principality Premiership.