Neath's title challenge was dealt a crushing blow as Swansea ripped the Welsh-Scottish league title wide open.
Victory would have almost assured the Welsh All Blacks the title, but the All Whites gatecrashed the party to virtually seal their place in next season's Heineken Cup.
Neath looked to have given their championship bid a huge boost when the hugely impressive Lee Jarvis dashed 40 metres after pouncing on his own chip forward to register the first try of the game.
His successful conversion was then matched by a delightful drop goal for the away side to race into an early lead.
But his opposite number Gavin Henson cut the deficit with his first penalty of the evening after 20 minutes.
Neath were powerless to prevent the All Whites from surging back into the match when Darren Morris muscled his way over for a try. Henson failed to convert from the touchline but the youngster added a second penalty on the half-hour mark to edge Swansea in front for the first time.
A drop goal from Jarvis in first-half injury time gave Neath a 13-11 interval lead, but a rare penalty miss after the break increased the pressure.
The Swansea pack turned the screw and their success at a scrum 13 minutes from time gave Henson the chance to emulate Jarvis and drop a goal under the posts. A carbon copy four minutes later sealed victory for Swansea leaving Neath's title bid laying in tatters.
The result leaves the door wide open for Llanelli, Newport or Cardiff to clinch the title.
The Scarlets will claim top spot if they can overcome Cardiff at The Arms Park on Friday evening. But should they slip up Newport could pounce if they were to win their two remaining fixtures against Pontypridd and Bridgend.
Cardiff are still in the hunt but they would have to run in a hatful of tries in their final game against Llanelli.
Whatever happens the gripping climax to the title has gone right down to the wire and this weekend someone will be celebrating the championship.
Nearly 40 players were involved in the first Wales Under 18 training session of the season. WRU National Performance Manager Gethin Watts is excited at the potential shown by the group and expects the Regional Under 18 Championship to hone their skills even further.