Gloucester cling to the thinnest of qualification threads but they are within a gnats crotch of elimination after blowing a great opportunity against Cardiff Blues at Kingsholm.

They squarely failed to make the most of a man advantage for almost an hour, confused what should have been a long-range kicking game for territory with a midfield miss-mash in the second half and in the end, despite all their efforts, came second in the physical confrontation.

In many ways, this defeat should not come as a surprise because it's happened before and Gloucester have not been playing well or consistently enough for some time but here they got themselves into a great situation against arguably the form side in the competition.

Cardiff are more than the sum of their parts. Their front five, minus Paul Tito, is not likely to frighten the daylights out of anyone in this competition but they are durable, physical and smart.

Throw in the blindingly brilliant Martyn Williams, who not only turns over an indecent amount of ball but seems to run in his own private channels, a thunderous carrying game from Andy Powell and a brilliant cameo from Xavier Rush and it is easy to appreciate how they manipulated the contest late on.

They also have a backline out of the giant category and even without Tom James, who was red carded for going head to head with Olivier Azam, Cardiff were so comfortable they never once took a man from their forward pack to cover their backline deficiencies.

Gloucester's kicking game was the right one on a sticky, cloying surface but it need to be long to establish field position. It wasn't for long enough and when they did get within range to attack, they needlessly kicked ball away - it summed up their afternoon. The talent is obvious but this was a defeat in the top two inches as anywhere else.

Amongst the defeat, there were some excellent contributions. Luke Narraway got about as ever, Alex Brown's work rate and defensive qualities were stratospheric, Alasdair Strokosch's effort was total.

To say they were not committed or any other such comment would be frankly ridiculous. The desolation in the dressing room told its own heart-breaking story. They worked themselves into the floor but came up short.

They got a rollicking start. Cardiff were penalised for dropping a scrum and Olly Barkley banged over a monster penalty from two metres inside his own half.

The opening stages dripped with vigour and confrontation. It was almost a battle between who could make the biggest tackle, the longest carry or quality turnover and after Leigh Halfpenny had levelled the scores, Powell showed his carrying prowess from the re-start and Maama Molitika, all haircut and aggression, came into support but the Blues wasted a great opportunity with a forward pass to the left.

One team threw a punch and then the other. This time it was Gloucester's turn. Lamb and Barkley started things up the centre, Iain Balshaw looked to get down the left before Strokosch, a brilliant flick pass from Matthew Watkins and Olivier Azam all maintained the move before Apo Satala wriggled to beneath the sticks and although he may have lost the ball, Barkley nudged over the penalty for a 6-3 lead.

Cardiff then lost James with a red card and Barkley made it 9-3 before half-time with his third successful penalty.

It would be wrong to say it was all Gloucester but they had rightly claims to have dominated the first period although their lead was a slender one.

That lead became almost non-existent when Marco Bortolami was penalised for blocking and Halfpenny made it 9-6 after 42 minutes.

The contest then entered its vital phase. Both teams had at least tried to play up to this point and you sensed that one try-scoring opportunity for either side would be decisive. The crowd sensed it too. The atmosphere was electric - nervous, vocal and partisan, particularly from the Cardiff hordes - and when Gloucester battered away through a series of phases it looked as though they may engineer the score that would break the contest open.

But Lamb opted to send a little roller in behind the defence, Halfpenny swept up and Cardiff responded. Barkley was turned over in midfield looking to run back and from the penalty, Cardiff went to the corner.

It was Powell who blasted through a gap, before Gareth Williams took over and got within inches of the line despite a brilliant tackle from Watkins and Brown saved the day by somehow getting his body beneath the ball when scrum-half Jason Spice went for the whitewash.

There was a sense that may have been the defining moment. Gloucester held their scrum steady and cleared before Barkley nudged over a 60th minute penalty when Cardiff were penalised for off-side.

That made it 12-6 to Gloucester and in the context it was a significant advantage without ever being convincing. It has been said before that the Heineken Cup can do special things to teams and the same is true with Cardiff.

They made a telling replacement by introducing Rush and it changed the context of the game. His first carry was of the withering, thunderous variety and Halfpenny made it 12-9 with a 70th minute penalty as Cardiff's belief and withering physicality grew.

Gloucester's confidence and management of the situation almost ebbed away at once. The two backs they didn't have, Mike Tindall and Olly Morgan, were just the sort of individuals they needed now - Tindall for his physicality and Morgan for his safety and kicking option - but Cardiff absorbed everything and then plundered the try that won the game.

Rush was involved twice and when possession came right, replacement lock Bradley Davies reached over the pile of bodies to score. It was a sickening, maddening conclusion and one hard to deny Cardiff. They were worth their victory for their sheer effort alone and leave Gloucester requiring something out of the ordinary.