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.
Whenever Bedlinog tackle Penallta a massive fixure is guaranteed but this Sunday there will be even more emphasis placed on the two rivals when they contest the SSE Swalec Plate final at Principality Stadium.
Ahead of their SSE SWALEC Bowl Final clash with Taffs Well at Principality Stadium on Sunday, Burry Port share their #FABXV nomination with WRUTV in the search for Welsh rugby's greatest volunteers. Everyone can get involved by sending nominations via twitter to @WRU_Community using the hashtag #FABXV
Cardiff Blues prop Gethin Jenkins and Ospreys centre Ben John look ahead to the first game at Principality Stadium in Saturday's double header which is promising to be a special occasion for all Welsh fans.
Carmarthen Quins Director of Rugby Ian Jones and committee member Jeff Thomas along with Llandovery chairman Handel Davies look ahead to Sunday's SSE SWALEC Cup showdown where both teams are out to prove 'West is best'
SWALEC ambassador Shane WIlliams is looking forward to Sunday's Finals Day where the Cup, Bowl and Plate offers a great opportunity for players and teams to experience the magic of playing at Principality Stadium
Carmarthen Quins coach Richard Kelly believes it is an exciting time to be part of the Scarlets region as his side take on local rivals Llandovery in the SSE Swalec Cup final on Sunday, as WRU TV's Graeme Gillespie discovers
Scarlets long serving prop Phil John talks to WRU TV's Graeme Gillespie about Judgement Day IV and SSE Swalec Cup finals day. The last time Llandovery were in the cup final in 2007, the Drovers claimed the spoils with Phil playing a major role in the engine room.
Meet Aberdare coach Luke Thomas whose #FABXV nomination goes to super volunteer Daz with a whopping 10 things he does for the club each week, all except the ironing! You can also join in the search for Welsh rugby's greatest volunteers, by sending your nomination via twitter to @WRU_Community using the hashtag #FABXV
SSE Swalec Cup kings Pontypridd travelled to Swansea, fully expecting a return to their second home but Llandovery had other ideas as they also sought victory in the semi-final to earn the right to play the final at Principality Stadium