Cardiff's second-half comeback counted for nothing after a loose pass on halfway let in Ebbw Vale for the decisive converted try that settled their fate after an action packed encounter.
The Blue & Blacks looked down and out at 0-16 at the interval. The nearest they had come to scoring were a couple of penalty goal atempts from 25 and 45 metres by Gareth Davies that rebounded off the woodwork.
But there was far more purpose and pace after the break with Rhys Shellard striking quickly for a fine try, an even better one by debutant Tim Mosey, and when Garry Horrigan touched down for a third and Davies converted, the Blue & Blacks were 25-16 ahead.
Then the old failings kicked in. As Howard Stone siad afterwards, 'We seem incapable of killing a game off'.
No one would argue with that. Aaron Bramwell kicked his fourth penalty for the visitors and, after left wing James Lewis had intercepted for his second try of the game, the centre converted from the edge of touch for a famous Vale victory.
Stone's other comment about the need for the side to play for the full 80 minutes was equally apposite. Their first half performance was the stuff of nightmares. Possession from set-piece and the contact situations was at a premium and the penalties went at a ratio of two-to-one against them. A grateful Bramwell slotted three goals from 40-metre range and with the class kick of the half converted Lewis' first try from the touchline.
The writing was on the wall for the Blue & Blacks but, just when everyone in the crowd had given up hope, the Jekyll and Hyde nature of their persona surfaced again. Suddenly they were attacking with some structure and their three tries and 10 points from Davies' boot put them on the brink of not only an unlikely win, but a bonus point as well.
Sadly, the plot changed again and the Bramwell-Lewis one-two settled a lively game.
Tim Mosey had proved an interesting acquisition at full-back, undeniably better in attack than defence but growing in confidence the longer the game went on. Luke Ford was the only other attacking threat behind the scrum. Up front, some tough questions will need to be asked about the continued experimentation with John Yapp at tight-head prop but Craig Everett is becoming increasingly influential in the back row.