The home side were keen to start the game positively but it was the Ospreys who opened the scoring when after only two minutes outside-half Adam Rowlands slotted over a short-range penalty.
The North Wales side's response was almost immediate with prop Rhodri Evans crashing over from short-range and fly-half Lewis Barker adding the extras to give the home side a 7-3 advantage.
The game was then interrupted due to a serious injury to RGC 1404 prop, Joe Simpson, and the match was moved to the adjoining pitch, whilst an ambulance was waited for.
Shortly after it resumed the home sides lead was extended further when Barker added a penalty to his earlier conversion. However while the home side started to dominate territorially, it was the Ospreys who finished the half the stronger when full-back Dominic Carroll crossed the whitewash shortly before the half-time whistle.
The second half, now back on the main pitch, began in similar vein to the first with the home side seemingly in control both territorially and possession-wise, but unable to add any additional scores bar a single penalty from Barker.
Then half-way through the second-half the dam was broken when three tries were scored in 10 minutes.
The first from winger Jason Blackmore, the second from flanker James Grundy after a flowing move involving most of the backline and the final one scored when full-back Dion Jones raced in from 40 metres.
With Barker converting all three the RGC 1404 side found itself leading 34-8, a score-line that would be maintained right up until the final whistle.
Marc Roberts the WRU Performance Manager for North Wales said, "We have to be happy with today's result as we have never beaten the Ospreys at age grade level.
"However to be honest the coaches, players and management are all aware that there are areas of our game that could have been better! Everyone will take confidence from the final score but we know that there is more to come from this squad.
"We have some big challenges ahead of us with Northampton Saint U19s and then the Blues but we will continue to work hard to look for consistent improvements."