Simon King's side were impressive against a much bigger French outfit and despite going in 9-7 down at the break, King's side were rarely under pressure.
After two France penalties, Blues and Aberdare flanker Thomas Young was the first on the score sheet for Wales with a try converted by Ospreys and Porthcawl fullback Tom Prydie. The French added a further penalty before the break but it was Wales all the way in the second half.
There were tries from Dragons and Llandovery College tight head prop Rhodri Jones, Scarlets and Whitland scrum half Aled Davies, and Prydie, who added a further conversion and penalty to take his points tally for the game to 12.
King was pleased with the result and performance of his young side away from home. "The boys showed great maturity and composure to come away with this win and it has certainly kick-started our Six Nations campaign.
"We had a number of missed scoring opportunities but to dominate France on their own patch, and not concede any tries is no mean feat.
"The performance certainly provides us with a platform to work on before we welcome Italy to Aberavon in a month's time."
Wales Under 18 play Italy at Talbot Athletic Ground on Sunday 22 March before travelling to Parma at Easter to play England, Ireland and Scotland at the Under 18 Six Nations festival.
Wales v France:
Tom Prydie (Ospreys); Luke Williams (Scarlets), Ben John (Ospreys), Jack Gadd (Exiles), Eli Walker (Ospreys); Matthew Morgan (Ospreys), Aled Davies (Scarlets); Rowan Jenkins (Scarlets), Ieuan Davies (Blues), Rhodri Jones (Dragons), Lloyd Peers (capt, Ospreys), Tom Crandon (Dragons), Edward Siggery (Scarlets), Thomas Young (Blues), Dan Baker (Ospreys).
Replacements (all used):
Lewis Smout (Blues), Gareth Harvey (Ospreys), Dan Evans (Blues), Mccauley Cooke (Blues), Grant Rogers (Dragons), Adam Jones (Dragons), George North (Gogledd), Dale Ford (Scarlets)
For further information, contact Liz Jones, tel 07736 056669 / firstname.lastname@example.org