The currency enjoyed by Cardiff in Europe has been limited since they appeared in the inaugural Heineken Cup final 12 years ago, but the introduction of an old-fashioned coin of the realm has clearly given them a lift. Two tries by Leigh Halfpenny propelled Cardiff Blues, as they now are, towards a dominant position in pool six and ensured that yet another Guinness Premiership club must take a hard road towards the knockout phase.

Gloucester were no more than a hair's breadth away from the considerable solace of two losing bonus points when James Simpson-Daniel knocked on a wickedly bouncing ball on the Cardiff line with only two minutes remaining. But that simply served to emphasise Gloucester's afternoon at the Millennium Stadium in a game in which three minutes of madness just before the interval proved a crushing blow to their hopes.

They had done so well to fight their way back from 10-0 down to take a four-point lead. Then they lost Ryan Lamb with a badly bruised hip after the fly-half had played exceptionally well and Olly Barkley, risking a tap pass that failed to find its mark, gave Halfpenny, aged 19 and one of the important players in Wales's under-20 campaign last summer, the chance to run in his second try from halfway.

When Ben Blair broke from the restart and found support from Jamie Robinson and Gareth Thomas, Gloucester had leaked 14 points and had all their work to do again. With a shaky lineout and indecision in their first line of defence, it was more than they could manage even though they controlled territory and possession in the last ten minutes with 14 men after losing Olivier Azam to the sin-bin.

Cardiff, though, always looked the more dangerous in broken play and they had, in Andy Powell, the outstanding forward on the pitch. Powell has been plagued by injuries over the past two seasons but has taken the opportunity provided by the enforced absence of Xavier Rush to play so well at No8 that he is now spoken of as the potential replacement in the Wales back row for the injured Jonathan Thomas.

“We showed a lot of character and togetherness to weather a few storms out there,” David Young, the Cardiff director of coaching, said. “We're very happy to have ten points from our first two games in Europe but it was just as important to make sure that Gloucester went away with nothing.”

There were injuries too, to Luke Narraway, who left with a damaged hamstring, as did Olly Morgan. Narraway's situation will concern England since he is their putative No8 next month and demonstrated why with the kind of wholehearted game he has been playing for his club all season. In addition, Gloucester chose to replace Lamb with Lesley Vainikolo rather than the more obvious Willie Walker.

The introduction of Vainikolo forced Barkley to move to fly half and Simpson-Daniel to centre whereas Walker would have been a like-for-like replacement and brings greater variety in attack. The reshuffle did Gloucester's defensive alignment no good and when they did start to dominate possession, midway through the second half, they were ten points down and desperately chasing the game.

Halfpenny's first try, three minutes into the game, did not show Morgan in the best of lights since the young wing's little feint baffled the full back completely. Blair's conversion marked the start of an afternoon - before a club-record crowd for a pool game of more than 27,000 - in which he finished with 17 points.

Barkley was just as accurate, converting from touch the try scored by Morgan which added conviction to Gloucester's efforts. It stemmed from a five-metre scrum conceded by

Ma'ama Molitika, who should have left a long kick by Lamb well alone rather than helping it over his own line. When Gloucester shunted Cardiff off their own scrum ball, Narraway sent Iain Balshaw over for the first of two tries but that was the high point for the visiting team.

They did reduce Cardiff's lead to three points when good hands by Barkley, Mike Tindall and Vainikolo created Balshaw's second but they were lucky not to see Thomas score from Nicky Robinson's cute kick into space. Robinson therefore took matters into his own hands. Cardiff forced a five-metre scrum and he stretched over from Powell's pick-up, opening a gap that Gloucester could not close.

Scorers: Cardiff Blues: Tries: Halfpenny 2 (3min, 38), G Thomas (40), N Robinson (62). Conversions: Blair 4. Penalty goals: Blair 3 (12, 21, 71). Gloucester: Tries: Morgan (23), Balshaw 2 (31, 49). Conversions: Barkley 3. Penalty goal: Barkley (18).

Scoring sequence (Cardiff Blues first): 7-0, 10-0, 10-3, 13-3, 13-10, 13-17, 20-17, 27-17 (half-time), 27-24, 34-24, 37-24.

Cardiff Blues: B Blair; L Halfpenny, J Robinson (rep: C Sweeney, 78), T Shanklin (rep: J Roberts, 54), G Thomas; N Robinson, J Spice (rep: R Rees, 68); G Jenkins (rep: S Morgan, 77), R Thomas (rep: G Williams, 59), G Powell (rep: T Filise, 54), D Jones, P Tito, M Molitika, M Williams (rep: R Sowden-Taylor, 75), A Powell.

Gloucester: O Morgan (rep: W Walker, 44); I Balshaw, M Tindall, O Barkley, J Simpson-Daniel; R Lamb (rep: L Vainikolo, 35), G Cooper (rep: R Lawson, 71); A Dickinson, O Azam (sin-bin, 70), C Nieto, M Bortolami, A Brown, P Buxton (rep: A Hazell, 54; rep: S Lawson, 72), A Strokosch, L Narraway (rep: A Eustace, 78).

Referee: A Rolland (Ireland). Attendance: 27,114.