With the Blues South game against the Scarlets falling foul of the weather, the North were able to improve their advantage at the top of the group.
High performance manager Gafyn Cooper said, "It was a wet and nasty evening as far as the conditions were concerned, but all credit to both sides, they put on an excellent show. The victory means that we have four from four now and that is something we are very proud of."
Smerdon completed his side's tally with three conversions whilst for the Dragons there was a try from centre Rhys Howells and eight points from the boot of full back Joseph Evans.
In the U20, the Ospreys were 20-13 winners over the Scarlets at Narberth; Nick Roberts and James Pike bagged tries and Leigh Halfpenny kicked two conversions and as many penalties. A try from centre Rhys Williams plus a conversion and two penalties from full back Daniel Evans kept the Scarlets in touch, but they were held out in the second half as the Ospreys closed off a significant victory.