In a high-tempo afternoon of schools rugby, all four schools produced some quality rugby and clearly enjoyed the occasion, buoyed by some vocal support from their schools.
Llanishen High won the Welsh Schools Under 18 Final, beating Ysgol y Preseli 19-17 after going 17-7 down at the break.
Ysgol y Preseli centre Elgan Wilson scored and converted Preseli's first try, Llanishen full back Gareth Vaterlaws providing his side's only score of the first half, converted by Lewis Marshall to take the score to 7-7. Preseli then went ahead through a try by Carwyn Vaughan, converted by Wilson who added a penalty to take the half time score to 17-7.
However, the Cardiff school mounted a second half comeback with tries for centre Owen Davies and No 8 Marshall.
Llanishen coach Harry Trelawny said, "This has been the best occasion a schoolboy could dream of being part of. To play with your mates for seven years and then to be picked in a squad to represent your school at the Millennium Stadium, the best rugby stadium in the world is certainly something to cherish, and to win makes it unforgettable.
"The occasion certainly brought out the best in the attitude and work ethic of our players and they showed a huge amount of self-belief to come back in the second half to win the game.
"Every team in the school was here supporting today and I'm sure that performance is something they will all aspire to achieve in the coming years. The players showed again today that hard work pays off."
Gethin Vobe, Preseli coach added, "The players are disappointed at the moment but they can be proud of their efforts when they look back and see what they've achieved this season.
"We lacked a bit of composure to close of our chances in the second half but Llanishen deserved to win in the end.
"Rugby is thriving in our school at the moment and this will only help in that regard. Our Under 14 side lost in the semi-finals of their Cup competition last night so things are looking good."
In the Under 11 Inter Schools Final, Dafydd Price scored two tries, Ryan Wilkins one and Seb Thomas scored three convenersions in Pontyclun's 21-0 win over Langstone Primary.