Funny thing, serendipity. Just before kick-off the Blues revealed that Ben Blair, their All Black full-back and leading points gatherer, had twanged a hamstring. Ostensibly, this was a big blow. In reality, it was nothing of the kind.
The reshuffle worked rather well. Jamie Roberts moved from wing to full-back, Gareth Thomas from centre to wing and Jamie Robinson, who would have been on the bench, wore No 12. It was Robinson who scored the Blues' first try, which set them up for a crucial victory, while the stand-off Dai Flanagan, who would not have played had Nicky Robinson been fit, took over the goal-kicking and scored 16 points with three penalties, two conversions and a drop goal. The drop goal came in injury time and deprived Stade of a losing bonus point.
"That may have a massive bearing," Dai Young, the Blues' coach, said. "The most important thing, though, was to get the win. We haven't won anything yet, we are not even in the quarter-finals, but we have put ourselves on the map. We're not the finished article but we have shown everybody that we're going in the right direction."
The Blues, and the Cardiff club before them, have been Wales' great underachievers but Young and his assistant coach Robert Howley the region are resigned to losing the former Test scrum-half to the Wales cause sooner or later have built a squad which has some depth. Yesterday they were able to introduce Martyn Williams in the second half, off the replacements' bench.
The Cardiff side have not graduated from the pool stage of the Heineken Cup in the last six years but they have a good chance of doing so this season. They picked up a bonus point when losing 12-6 to Stade Franais in Paris last week and the win here has put them top of Pool Three with 12 points, although Bristol, who play today, could join or overtake them.
They got off to a flier when Flanagan's clever inside pass released Thomas on a diagonal run towards the posts and he drew the last of the cover to send Robinson over. By the 21st minute the Blues were 13-0 in front, Flanagan contributing two penalties and a conversion. Stade sported a shocking pink outfit which attracted a blast of wolf whistles from some members of a capacity crowd but for most of the first half the Parisians were simply shocking.
When Roberts dropped a pass, Brian Liebenberg had a clear run to the line but he never looked like making it. On came Mathieu Bastareaud, who has to be one of the heaviest centres in the game. Big Bastareaud put in a couple of bullocking runs and for the first time Stade created a series of attacks, which resulted in an overlap for Julien Arias to score on the right.
At 13-7 Stade, somehow, were back in it but, given the balance of play, the scoreline looked more accurate when Tom James, appearing in midfield, shrugged off David Skrela's tackle and had the pace and power to leave everybody else in his wake. It was a startling try and it gave the Blues a 20-7 lead at half-time.
"It was a great finish," Young said. "Tom is as strong as most of our forwards. He's coming on with every game. He's a star of the future."
When the lock Paul Tito charged down Skrela's clearance two minutes into the second half it turned out to be a Christmas bonus. The ball skewed over the line towards the left corner flag and Tito showed amazing pace to beat Arias and dive for the try.
Perhaps the only regret for the Blues is that they had a lot of time to score a fourth try which would have given them a bonus point. Instead, Stade began to play with urgency and belief and three penalties from Skrela and a try by Antoine Burban once again had them trailing by only seven points, at 28-21.
For Burban's try, Thomas missed a straightforward tackle and there was another lapse when the Blues failed to capitalise on a numerical superiority after the Stade prop Rodrigo Roncero committed a blatant late charge on Thomas, who was chasing a kick head, and spent 10 minutes in the sin-bin.
When the Blues got into an attacking position their priority was not to score a fourth try but to send Stade home empty-handed. This was accomplished by Flanagan in the fourth minute of injury time. "Our preparation was poor and we got off to a bad start," Fabien Galthi, Stade's coach, said. "A quarter-final is probably dead for us."
Cardiff Blues: J Roberts; G Thomas, T Shanklin, J Robinson, T James; D Flanagan, J Spice (R Rees, 72); G Jenkins (J Yapp, 70), G Williams (R Thomas, 60), T Filise, D Jones, P Tito, M Molitika, X Rush (capt), R Sowden-Taylor (M Williams, 60).
Stade Franais: I Corleto; J Arias, S Glas (G Messina, 47), B Liebenberg (M Bastareaud, 37), J Saubade; D Skrela, J Fillol (A Albouy, 37); R Roncero, D Szarzewski (capt), P de Villiers (P Ledesma, 40), B Du Plooy, P Pape, A Burban, S Taylor, R Martin.
Referee: W Barnes (England).