Cardiff had to wait for just over an hour before breaking down a determined Ebbw Vale defence and finished with what appeared a runaway victory.
In fact, Ebbw had the match for the taking, but lacked a goalkicker, and just could not finish off breaks by Rhys Shorney and Richard Davies in particular.
It was 7-3 at the interval after skipper Martyn Williams had scored a try converted by Nick Robinson for Cardiff and scrum half Bryan Shelbourne had landed a Vale penalty.
When Shelbourne kicked another and teenage Cardiff debutant prop John Yapp became the 14th club player to be yellow-carded in as many games, Vale were back into the match.
However, centre Nick Walne scored two tries - his first of the season - and wing Dean Dewdney also crossed with Robinson landing three further conversions and two penalty goals, and the Vale heads went down.
Player-of-the-match Walne commented that Cardiff coach Dai oung had told his ide at the interval to keep playing the same angles and the scores would come. "It was just fantastic to play at centre instead of the wing. Now I can celebrate Christmas !"