They were ahead from the eighth minute, 13 points up at half-time, and 20 points clear at the finish. This was unlikely to unsettle the Pool D leaders, Harlequins, lost in Munster yesterday, but it was enough to secure Cardiff's place in the quarter-final play-offs on the first weekend of November.
Cardiff could also face these with more confidence after an impressive display of all-round competence. They held and eventually subdued the Bourgoin pack. Their tackling and foraging for the loose ball was swift and sometimes spectacular.
Determined not to be limited by the conditions, they conjured up two vital tries, both of them run in, not simply barged over. And they kicked their goals, Lee Jarvis's 16 points taking him past 100 in the competition.
Bourgoin, unused to this insidious kind of weather, did not adapt well. They are a solid, more than workmanlike side, but were perhaps surprised by Cardiff's expansive tactics and seemed torn between the wish to copy them and their natural instinct to keep things tight and release the ball only at the last minute.
Cardiff knew their own minds, swung the ball about from the start, and relied on their forwards to get across and cover the inevitable breakdowns when the slippery ball was mis-passed or mis-fielded.
This did not produce a welter of tries exactly. There was one from Justin Thomas on the right wing after 22 minutes, which cemented Cardiff's early advantage. And a second, an hour later, when Gareth Jenkins swung round the blind-side from centre to score in the corner.
But what Cardiff's policy also did was keep Bourgoin on the back foot and under pressure to guard their line which lured them into presenting chances for Jarvis to kick his four penalty goals.
It also added to Bourgoin's frustration. They had one good spell of counter- attack just before and after the interval, but it brought only two penalties from four attempts by their stand-off, Nigel Geany, and a heightened degree of friction between the two packs. Three times the Irish referee, Leo Mayne, brought the captains together to warn them about their teams' conduct, but there were no dismissals, and by prevailing standards this was a rugged rather than a brutal match.
Cardiff: Tries: Thomas, Gareth Jones,; Conversions Jarvis 2; Penalties Jarvis 4. Bourgoin: Penalties Geany 2.
Cardiff: B Ross; J Thomas, L Davies, Gareth Jones, N Walker; L Jarvis, R Howley; A Lewis (P Booth, 76), J Humphreys (capt), D Young (L Mustoe, 78), J Tait, D Jones (J Ring, 76) G Kacala, Gwyn Jones, S Williams (E Lewis, 62).
Bourgoin: D Janin (J Bohu, 54); L Leflammand, G Cassagne, S Glas, L Saunier; N Geany, N Guilhot; O Millou (D Morgan, 70), J-F Martin-Culet (D Frier,73), P Peyron (D Gomez, 70), M Cecillion (capt; H Dalde, 70), F Nibelle, A Chazalet (F Grange, 73), M Malafosse, P Raschi.
Referee: L Mayne (Ireland).Reuse content