Rob Sweeney wrote his name into the record books as he helped himself to 34 points in one of rugby's oldest and most bitter derby matches after coming on as a replacement.
The Swansea under-21 outside-half took over the pivotal role from Arwel Thomas 26 minutes into this pulsating match and set it alight with a hat-trick of tries and a 100 percent goal-kicking record.
By the end, the unknown youngster had become a local hero as he helped to provide Swansea's dismal season with a superb ending as they brought down
the curtain on their 127-year rivalry with Llanelli with a fantastic triumph.
This was the 365th clash between the two clubs and no-one had ever scored 34 points before in a match. Next season Swansea are amalgamating with
Neath to form a regional side, so there will never be a fixture like this again.
Neither will Sweeney ever experience anything like it again. It took him two minutes to grab his first try to kick-start the Swansea revival and by half-time he had steered the All Whites into a 32-26 lead after they had,
at one stage, been trailing by 18 points.
Better still, it took him only one minute of the second half to add his second try and two minutes later he completed his hat-trick to make his tally 28 points in 20 minutes.
He slowed down a little bit after that, but he went on to maintain an error-free goal-kicking record as he landed two more penalties to complete
Swansea's rout of their biggest rivals and avenge two heavy defeats at Stradey Park earlier in the season.
Swansea got off to a flying start with the first of wing Shaun Payne's brace of tries after only two minutes, but the Scarlets took a firm grip on proceedings for the rest of the opening quarter as they ran in four tries
to race into a 26-8 lead.
Wales under-21 scrum-half Mike Phillips darted clear for the first try and then made the second for his half-back partner Gareth Bowen with another superb break. The young Phillips is a superstar in the making.
Tongan blockbuster Salesi Finau grabbed the next try and centre Tal Selley bounced off Scott Gibbs to find a gap in the home 22 to race through for try number four.
At that stage it looked as though Swansea were going to slump to yet another home defeat - they had lost six of their 13 home games before this - but Sweeney had other ideas. Shortly after replacing Thomas he turned the game on its head with his quick thinking and his first try came after a strong burst from Swansea skipper Gibbs.
Wales under-21 fullback Gareth Swales was next to cross the Llanelli line and Payne's second try on the stroke of half-time helped to edge Swansea ahead once again.
Then came Sweeney's two try burst at the start of the second half and Llanelli's heads dropped. It was all Swansea in the second half and not even two tries in the final 10 minutes from the Scarlets could save their blushes.
Scorers: Swansea: tries: R Sweeney 3, S Payne 2, G Swales; Cons: R Sweeney 5; Pens: R Sweeney 3, A Thomas.. Llanelli: Tries: M Phillips, G Bowen, S Finau, T Seley, L Gross, A Yelland; Cons: G Bowen 5.
The WRU has teamed up with Crawshay's to tour Georgia in June. The side, which will be called the Crawshays WRU President's XV, will play Emerging Georgia twice, in a tour which supports the Welsh Government's efforts to grow relations between the two countries.
Wales Sevens are looking to re-group after a disappointing tournament last time out in South Africa. The next double leg in New Zealand and Las Vegas offers Gareth Williams a chance to redeem themselves.
Wales Women's head coach Rhys Edwards was at Llandovery to see the conclusion of an entertaining Women's Regional championship where any one of three teams were in contention for title glory on the last day of action.