Ryan Edwards and Mitch Eadie crossed for Liam Middleton’s side in response to Cardiff’s only try from centre Cory Allen.
But the game turned when the home side’s flanker Arthur Ellis was sent off in the second half.
“I felt we were in control of the match until the red card and things like that change games,” said Cardiff coach Martyn Fowler.
“We’re all extremely frustrated to have lost, it’s a game we could and should have won.
“The youngsters in our squad are really starting to come through now and against a big Bristol pack our front five fronted up well. We attributed ourselves brilliantly against a professional team but we should have won.”
It was Bristol who dominated early on with their forward dominance apparent. The first 10 minutes saw the English side camped in the Cardiff half and the pressure finally tolled when fly-half Matt Jones gave Bristol a 3-0 lead, succeeding with his second attempt after an earlier effort had struck a post.
After barely touching the ball in the opening exchanges, the restart saw Cardiff at least find themselves in the opposition half. And they soon earned a penalty only for Blue and Blacks’ fly-half Joe Griffin to see his difficult effort glance off the right hand upright.
In a scrappy game, there were few clear cut chances as the two sets of forwards saw most of the ball. Cardiff prop Lewis Smout was yellow carded for an infringement at a ruck and Bristol used their one man advantage to extend their lead to six points, Jones successful with another penalty.
For all their dominance though, Bristol were far from out of sight and they were soon pegged back by the boot of Griffin who made it 6-6 with two penalties of his own.
With the game needing a spark to get it going, Cardiff hooker Aaron Fowler nearly provided it. Intercepting a pass inside his own half, Fowler made it nearly 60 metres but lacked the pace to outbreak the covering defence. Looking for support, the hooker’s pass fell loose and although the ball was hacked on by captain Shaun Powell, Bristol winger Matt Williams covered to avert the danger.
Williams was then sent to the sin bin for a technical offence allowing Griffin to send Cardiff into the interval with a narrow 9-6 lead.
If the first-half was scrappy at best, the second started with a bang as Allen went over to extend Cardiff’s lead. Breaking away from the covering defence, the centre’s pace saw him survive a tap tackle attempt to take him all the way to the line. Griffin failed to add the conversion but Cardiff led 14-6.
Despite dominating most of the first half, Bristol seemed shocked by their deficit and they soon responded. After earning a kickable penalty in the Cardiff half, Bristol replacement Tristan Roberts opted to kick to touch. And they were rewarded when following the lineout, winger Edwards crossed under the posts.
It looked as if Bristol had knocked on in the act of scoring but the try was given. Roberts added the simple conversion to narrow Bristol’s deficit to a solitary point.
With the game in the balance, the game then swung in Bristol’s favour when Cardiff flanker Jenkins was dismissed by Scottish referee Cammy Rudkin following an altercation at a ruck. Bristol lock Mariano Sambucetti was also yellow carded but the home side were now up against it.
Following the dismissal, Bristol should have been out of sight but Roberts put both a penalty and a drop goal attempt wide. Referee Rudkin was at the centre of the action, then disallowing what looked like a clear second try for Edwards.
Collecting a Roberts chip through, the Bristol winger looked to have touched down but was adjudged to have knocked on in the act of scoring.
With a man advantage, the visitors were dominating possession and Roberts put his side back into the lead with a penalty.
And they made sure of the win when No. 8 Mitch Eadie went over late on. Roberts added the conversion and the final whistle went just minutes later.
