Toulouse so lost their composure in a violent first half that it seemed Cardiff would gain revenge for last season's 21-18 defeat at the Arms Park but the brilliance of the French centre Thomas Castaignede, who scored one of his side's four tries and kicked 10 points, was finally enough to overcome a weary Cardiff, who were playing their third European tie in eight days.
Pool D is living up to the "Group of Death" label but for 40 minutes it appeared Toulouse were willing to give an old tag a new slant by committing suicide. Seemingly forgetful of the fact they beat the Welsh club back in January by virtue of their superior rugby, the French appeared intent on taking a more violent approach. Soula, their shaven-headed hooker, took the brunt of the battle upon himself. He was warned, along with several other forwards, after the second huge punch-up in only the sixth minute of the game. He took no notice of the Scottish referee, Ray Megson, and quickly earned a yellow card for kicking Cardiff's full-back, Justin Thomas, in the back as he lay on the ground.
By that stage Toulouse were leading 5-3 after Castaignede had scythed through for a wonderful individual try following an early penalty for Cardiff's 20-year-old flyhalf Lee Jarvis. Soula was then spotted by a touch judge punching and kicking another Cardiff forward to earn an instant dismissal in the 24th minute. Even then he seemed reluctant to go without one final bout as he turned on his team-mate Christophe Deylaud before being dragged off.
Cardiff hung on for a 12-11 lead at the break thanks to the faultless kicking of Jarvis, but during the second half it was the Cardiff forwards who faded and their numerical advantage counted for little against the tight support play and quick rucking of the home pack.
Emile Ntamack put Toulouse ahead in the 51st minute after the full-back Ougier had danced through the ponderous Cardiff forwards in a blindside run. Within five minutes the Welsh club were further behind as the left wing David Berty collected the first of his two tries.
Cardiff rallied enough for their centre Gareth Jones to squeeze in for a try but a drop goal from Deylaud restored Toulouse's healthy advantage, and when Berty shrugged aside Nigel Walker for his second try their victory was complete.
Toulouse: S Ougier; E Ntamack (capt), M Marfaing, T Castaignede, D Berty; C Deylaud, J Tilloles; C Califano, P Soula, J Jordana, F Bellot, H Miorin, D Lacroix (M Marfaign, 71), S Dispagne, H Manent.
Cardiff: J Thomas; S Hill, M Hall, G Jones, N Walker; L Jarvis, R Howley; L Mustoe, J Humphreys, D Young, J Wakeford, D Jones, H Taylor (capt), E Lewis, M Bennett ( J Ringer, 72)
Referee: R Megson (Scotland).