Fly half Hannah Jones scored a hat-trick of tries with centre Robyn Wilkins, who has played for the Ospreys senior side, also crossing twice as the Ospreys backs ran riot. Wilkins added 13 points with the boot in a 53-5 win.
The Dragons had actually started the better of the two sides but the centre pairing of Wilkins and Elli Norkett proved the difference as they, alongside outside half Jones, controlled the game.
In the closely fought opening exchanges, the home side had seen most of the ball though had they failed to get outside of their own half.
And the Ospreys soon showed them how to be clinical when opportunities came their way as Jones dotted down for the opening score. Wilkins converted and then added a try of her own as her side moved out of sight.
After a slow start, the Ospreys were now well on top, Wilkins and Norkett proving a powerful combination at centre, one the Dragons failed to live with. Wilkins added a simple penalty before a third try saw the Ospreys boast a comfortable half time lead of 22-0.
The scoring continued after half time with Kelsey Boast crossing in the corner and Jones intercepting a midfield pass to run in for her second score.
With the game sewn up, the Ospreys were trying to run the ball from all parts and the try of the day soon followed. Picking the ball up well inside her own 22, Norkett had very little options but it mattered little as she shrugged off a number of would-be tacklers to take her the length of the field for a sensational score.
The Dragons were struggling to deal with the power and pace of the Ospreys but did get themselves on the scoreboard with a try from centre Robyn Harris.
It was a brief respite though as Jones completed her hat-trick and Wilkins added a second to put the seal on a comfortable win.