Toulouse extended their lead at the Pool Five summit with a 26-13 victory over the Dragons, ending the hosts' slim European aspirations at Rodney Parade on Saturday.
The three-time European champions eased seven points clear in Pool Five - closest challengers Bath visit Glasgow on Sunday - after subduing a spirited Welsh effort.
Tries during the opening flurries of each half by wings Maxime Medard and Cedric Heymans emphasised a gulf in class, although Toulouse still had to dig deep.
Frederic Michalak kicked a drop-goal and two penalties that underlined early Toulouse dominance, while David Skrela converted Medard's fourth-minute touchdown, yet the Dragons gave it their best shot.
Prop Rhys Thomas scored a try six minutes before the break, with fly-half James Arlidge booting eight points, but Toulouse were always capable of moving up a gear when it mattered.
Medard finished off the Welsh side by claiming his second try after 54 minutes, and then it was merely a question of whether or not Toulouse would claim a potentially-priceless bonus point.
The fact they failed owed everything to a Dragons pack that worked itself to a standstill, denying Toulouse one final opportunity.
Assuming Bath triumph at Firhill tomorrow, Toulouse's trip to Bath next month will decide the group.
And the reigning French champions - Heineken Cup winners in 1996, 2003 and 2005 - will fancy their chances of ending Bath's European adventure.
The unbeaten group leaders will feel satisfied at a job well done - despite the lack of a bonus point - leaving the Dragons reflecting on pool stage elimination two games inside the distance.
The Dragons had endured a difficult week after their former Northampton centre Marc Stcherbina suffered a serious neck injury during last Saturday's 26-7 defeat in Toulouse.
Stcherbina, who underwent surgery as a result, is now in a Bristol hospital after returning home from France by air ambulance on Thursday. He was replaced at inside centre by Ashley Smith.
Toulouse, meanwhile, paraded their traditional galaxy of international stars as they targeted a fourth successive group victory in the quest for yet another Heineken Cup quarter-final appearance.
And Toulouse took less than four minutes to cut the Dragons' defence open as Skrela's floated pass found Medard, who nonchalently kicked ahead and gathered a kind bounce.
Skrela converted in his final act before going off injured after being on the receiving end of Dragons number eight Joe Bearman's crunching tackle.
Michalak merely took up the baton from Skrela though, booting two penalties and a drop-goal during a fifteen-minute spell that saw Toulouse effortlessly move 16-0 ahead.
The Dragons were in danger of suffering a thumping defeat, yet their response stirred the Rodney Parade faithful, and they trooped off at half-time firmly back in contention.
Bearman's lineout catch and pass created sufficient space for Thomas to crash over, before the Wales prop came agonisingly close to claiming another try, but he knocked on while crossing Toulouse's line.
An Arlidge conversion and penalty slashed the interval deficit to just six points, raising expectations the Dragons could add another significant French scalp to their Heineken Cup collection after defeating Stade Francais, Perpignan and Castres in previous European campaigns.
But Heymans and Medard - two of the European game's deadliest finishers - struck during a third quarter when Toulouse seemed capable of just flicking a switch when they needed to.
At 26-13 adrift, the Dragons found themselves facing a damage-limitation exercise, yet they could not escape from suffocating Toulouse pressure, and Medard's pace continued to cause them major problems.
Referee Alain Rolland lectured rival captains Tom Willis and Yannick Jauzion following a late dust-up involving several players, but he opted against brandishing any cards, Toulouse having inflicted their punishment where it mattered most - on the scoreboard.
Pen: Alridge 2
Tries: Médard 2, Heymans
Pen: Michalak 3
Dragons: 15 Jason Tovey, 14 Gareth Wyatt, 13 Rory Sidey, 12 Ashley Smith, 11 Tal Selley, 10 Shaun Connor, 9 Wayne Evans, 8 Joe Bearman, 7 Colin Charvis, 6 Hoani Macdonald, 5 Luke Charteris, 4 Adam Jones, 3 Rhys Thomas, 2 Tom Willis (c), 1 Adam Black.
Replacements: 16 Steve Jones, 17 Gethin Robinson, 18 Danny Lydiate, 19 Jamie Ringer, 20 Robert Lewis, 21 Rhodri Gomer Davies, 22 Phillip Dollman.
Toulouse: 15 Clement Poitrenaud, 14 Maxime Médard, 13 Florian Fritz, 12 Yannick Jauzion, 11 Cédric Heymans, 10 David Skrela, 9 Byron Kelleher, 8 Shaun Sowerby, 7 Thierry Dusautoir, 6 Yannick Nyanga, 5 Patricio Albacete, 4 Fabien Pelous, 3 Benoit Lecouls, 2 William Servat, 1 Jean-Baptiste Poux.
Replacements: 16 Virgile Lacombe, 17 Dan Human, 18 Salvatore Perugini, 19 Gregory Lamboley, 20 Jean Bouilhou, 21 Frédéric Michalak, 22 Gaffie Du Toit.
Referee: Alain Rolland (Ireland)
Touch judges: Mark Hermin (Ireland), Richard Kerr (Ireland)