More than 350 pitched up at The Gnoll to see the two sides battle it out in an evenly balanced contest. But it was the visitors who left with a smile thanks to messrs Scarf and Gough.
Alex Wilkins with a try and a penalty from Nicky Roberts (Brynteg School and Pencoed Rugby Club) put the Ospreys in a decent position, but Scarf's first half try and a second, after the break, from Gough (Coed y Lan School and Ynysybwl Rugby Club) made sure of the points.
Christian Bala (Neath College and Merthyr Rugby Club) converted Scarf's score and Celyn Ashton (Treorchy Comprehensive and Treorchy Rugby Club) improved Gough's conclusive try.
In the other game at Under 18 level, the Dragons lost out, 23-15, to the Scarlets at Abertillery Park.
A penalty from Phil Williams was not enough to earn Blues South Under 16s a second successive victory of the season at
Williams knocked over his kick before the interval to keep the Blues South in touch, but the Scarlets were too strong and ran away with the spoils courtesy of two tries from Matthew Lemon and a third from Geraint Peachment.
A try from Jason Tovey of Cwmcarn School and Risca Rugby Club, plus a conversion and a two penalties from Abertillery's David Langdon should have been enough to earn the Dragons Under 16s victory over the Ospreys at the Old Parish, Maesteg.
However, the Ospreys, who lost their opening game against Blues South last month, snatched victory from the jaws of defeat courtesy of an injury time try from hooker Dean Ronan (
Ronan's try brought the Ospreys to within a point, but Nic Damjanovic converted from wide out to secure a welcome home success.
Tovey's try, after some excellent work from the Dragons' pack, plus Langdon's conversion and first penalty, left the Dragons 10-7 to the good at half time. But after Langdon's second penalty midway through the second half, the Ospreys hit back and took the spoils.
Llanelli Scarlets 14
Newport Gwent Dragons 15 Llanelli Scarlets 23