The Ospreys threw Heineken Cup Pool 2 wide open on Saturday with a well-deserved 17-6 win over Toulouse at Liberty Stadium.
The result, combined with Leicester's win in Treviso, means that Toulouse and Tigers are separated by a single point at the top of the pool with the Ospreys still in with a shout of qualifying for the quarter-finals.
An uncharacteristically high error-count from Toulouse allowed Ospreys to lead from start to finish with a wonderful try from Eli Walker proving to be the decisive moment just after the hour mark.
Ospreys were good value for their 9-6 lead at half time having enjoyed the lion's share of both territory and possession.
In fact, the three-point gap was not a fair reflection of the hosts' efforts in the opening stanza but some outstanding defence from Toulouse, spearheaded by Louis Picamoles, and a neat drop goal from Jean-Marc Doussain just before the break meant that the former champions were still very much in the game when the teams swapped ends.
Ospreys drew first blood when Dan Biggar slotted an early penalty. A drop goal from the home fly-half doubled the lead at the end of the first quarter.
Ospreys were struggling against arguably the best scrum in Europe but Biggar has making life difficult for Maxime Medard, peppering the rusty-looking France full-back with high balls.
Despite Patricio Albacete seeing yellow for stupidly shoeing Ian Gough on the deck, Toulouse were able to pull three points back when Doussain found the target from the kicking tee.
Another period of sustained pressure from the Ospreys yielded only three points from a penalty, meaning that Doussain's drop had Toulouse within striking distance at the interval.
But the addition of Adam Jones changed the situation at scrum time and Biggar's third penalty opened the gap back to six points on the hour mark.
Then came the try from Walker, who shrugged off a poor attempted tackle from Yoann Huget, to give the Ospreys some breathing room.
The closing stages were filled with drama as Gael Fickou produced a sublime piece of scrambling defence to deny Ashley Beck in-goal.
The TMO decided that Justin Tipuric had prevented Christopher Tolofua from grounding in ball and Toulouse butchered a clear chance with seconds remaining, sending them back to France without a losing bonus point.
Pens: Biggar 3
Yellow card: A. Jones
Yellow cards: Albacete, Bouilhou
Ospreys: 15 Richard Fussell, 14 Ross Jones, 13 Andrew Bishop, 12 Ashley Beck, 11 Eli Walker, 10 Dan Biggar, 9 Kahn Fotuali'i (c), 8 Joe Bearman, 7 Justin Tipuric, 6 Ryan Jones, 5 James King, 4 Ian Gough, 3 Campbell Johnstone, 2 Richard Hibbard, 1 Ryan Bevington.
Replacements: 16 Scott Baldwin, 17 Duncan Jones, 18 Adam Jones, 19 Lloyd Peers, 20 George Stowers, 21 Rhys Webb, 22 Matthew Morgan, 23 Tom Isaacs.
Toulouse: 15 Maxime MÃ©dard, 14 Vincent Clerc, 13 Yann David, 12 Gael Fickou, 11 Yoann Huget, 10 Jean-Marc Doussain, 9 Luke Burgess, 8 Louis Picamoles, 7 Thierry Dusautoir (c), 6 Jean Bouilhou, 5 Patricio Albacete, 4 Yoann Maestri, 3 Cencus Johnston, 2 Gary Botha, 1 Vasil Kakovin.
Replacements: 16 Jean-Baptiste Poux, 17 Yohan Montes, 18 Roman Millo-Chluski, 19 Yannick Nyanga, 20 Gregory Lamboley, 21 SÃ©bastian BÃ©zy, 22 Yannick Jauzion, 23 Christopher Tolofua.
Venue: Liberty Stadium
Referee: George Clancy (Ireland)