Jonathan Davies scored a hat-trick for the Probables against the Possibles.
The Probables carried too much firepower and class as the Possibles failed to live up to expectations as the shadow Test team romped to a comfortable 55-7 victory at a packed out Liberty Stadium.
Jonathan Davies led the way with a hat-trick while Dan Biggar contributed 20 points with an assured display from fly half.
From the moment winger Jordan Williams, the only uncapped player in the starting XV for the Probables, dived over in the corner in the third minute, the men in red dominated proceedings.
The Possibles simply couldn't get their hands on the ball as the Probables seized control in the first half by romping over for five tries.
Dan Biggar scampered over after Taulupe Faletau outflanked Andrew Coombes out wide and set the Ospreys fly half free. After adding the conversion and a penalty, Biggar immediately put the Probables on the front foot.
Davies made light work of scoring two tries in quick succession as the Possibles defence was shredded to bits.
The match was 33 minutes old before the Possibles made any inroads in attack but despite Coombs and scrum half Gareth Davies' best efforts, the move fizzled out.
Liam Williams forced his way over in Dan Fish's smothering tackle just before the break to give the Probables a 34-0 lead at the break.
Things didn't get any easier for the Possibles after the break when replacement Scott Baldwin barged his way over four minutes into the second spell.
Biggar then spotted a gap and sent Davies over for his hat-trick as the Ospreys pivot took his tally to 18 points for the evening with the simple conversion.
With the Probables making a raft of changes the game then stagnated but urged on by the crowd, the underdogs finally showed some bite when scrum half Gareth Davies eluded Josh Navidi and powered his way through Alex Cuthbert's tackle to surge over. James Hook landed an excellent conversion to stop the rot, momentarily at least.
With the Possibles finally getting some possession the game opened up with Hook, James Davies and in particular Matthew Morgan posing a threat but it was the Probables who had the final word when Jordan Williams dived over on the stroke of full time with Biggar adding a touchline conversion to add the icing on the cake for the victors.
Probables: Try: Jordan Williams (2), Biggar, Jonathan Davies (3), Liam Williams, Baldwin; Con: Biggar (6); Pen: Biggar.
Nearly 40 players were involved in the first Wales Under 18 training session of the season. WRU National Performance Manager Gethin Watts is excited at the potential shown by the group and expects the Regional Under 18 Championship to hone their skills even further.