Steffan Ciccotti, a 17-year-old marimba player from Kilgetty, came third in the 2009 Texaco Young Musician of Wales competition.
The prize was presented at the competition's final, hosted by former Blue Peter presenter Gethin Jones, on Saturday night where Steffan moved the judges with his performance of Fugue in G minor by Johann Sebastian Bach. He was one of five finalists to perform in front of a panel of distinguished judges.
Steffan collected a Texaco Young Musician of Wales trophy and £500 prize money for his solo and concerto performance with the Cardiff Philharmonic Orchestra.
First place and £1,000 was won by Steffan Morris, a 17-year-old cello player from Neath.
His prize comes after months of preparation, following preliminary rounds and regional finals across Wales, in which more than 80 musicians took part. His interest in music first started aged just 10.
David Shaw from Conwy and Ben Creighton Griffiths from Cardiff took runner-up positions.
Tom Kovar, general manager of Chevron's Pembroke refinery, said: "The talent at this year's final was exceptional, which made the judges' job even more difficult than usual.
"We are committed to supporting the local community and in particular encouraging young people in the fields of sport, education and the arts. I would like to congratulate all this year's finalists as making it to the final is a great achievement in itself, especially as they have beaten off competition from over 80 other talented young musicians along the way."
This was the 11th of the biennial competitions sponsored by Texaco and organised in partnership with Côr Meibion De Cymru, the South Wales Male Choir.