A 15-all draw with Leicester at Liberty Stadium on Saturday effectively brought an end to the Ospreys' Heineken Cup campaign.
The result also means that Tigers relinquish top spot in Pool Two to Toulouse, who beat Treviso with a bonus point to set up an almighty showdown at Welford Road next week.
A late Jonathan Spratt try earned the Ospreys a well-deserved draw after they had led for much of the game before two tries in the final quarter put Leicester in front.
Richard Cockerill rotated his starting line-up after last week's controversial Premiership win at Worcester, with an almost completely fresh pack, and several changes in the back line. Ospreys coach Steve Tandy was able to recall Richard Fussell at full-back and Kahn Fotualii at scrum-half, as well as making several changes in the forwards.
Tandy made one late change during the warm-up, with scrum-half Tom Habberfield replacing Ross Jones on the wing, to make his Heineken Cup debut.
The Ospreys were keen to keep up their great home run, with eleven wins on the bounce at the Liberty Stadium. The normally reliant boot of Dan Biggar was off target with three early missed penalties, the Welsh international hitting the woodwork twice.
Fotualii showed his danger, taking the game to Leicester. A great move, keeping the ball alive through the phases, led to Biggar landing his first successful kick of the day on the half-hour mark.
A moment of controversy came moments later, as Justin Tiperic chased his own kick, and was impeded by Matthew Tait as he charged to catch the ball on his way to the line. Referee John Lacey decided there was no infringement, and Leicester were left to breathe a sigh of relief.
But Leicester's defence had no answer to the Ospreys' first try, as Joe Bearman stepped inside three tackles to go down for Biggar to convert.
Toby Flood reduced the arrears with a late penalty to go into half-time at 10-3 to the Ospreys.
Ben Youngs scored Leicester's first try of the game just after the hour, after Flood had broken the gain line, with Martin Castrogiovani putting the scrum-half in a great position to take advantage. Flood converted to equalise at 10-all, and leave the game on a knife-edge as it entered the final period.
With less than ten minutes to play, Niall Morris put down in the corner after powerful play by the Leicester forwards -a decision made by the TMO - as the winger was chased to touch. Flood missed the difficult conversion, but Leicester finally had the second score they wanted.
But Eli Walker created the perfect platform for the Ospreys to equalise, on a diagonal run through the Leicester defence, and Spratt went over in the corner. Biggar missed the conversion attempt, leaving the game tied on the full-time whistle.
Tries: Bearman, Spratt
For Leicester Tigers:
Tries: Youngs, Morris
Ospreys: 15 Richard Fussell, 14 Tom Habberfield, 13 Tom Isaacs, 12 Andrew Bishop, 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 Adam Jones, 2 Richard Hibbard, 1 Ryan Bevington.
Replacements: 16 Scott Baldwin, 17 Duncan Jones, 18 Campbell Johnstone, 19 Lloyd Peers, 20 Sam Lewis, 21 Rhys Webb, 22 Matthew Morgan, 23 Jonathan Spratt.
Leicester Tigers: 15 Mathew Tait, 14 Niall Morris, 13 Manusamoa Tuilagi, 12 Anthony Allen, 11 Adam Thompstone, 10 Toby Flood, 9 Ben Youngs, 8 Jordan Crane, 7 Julian Salvi, 6 Steve Mafi, 5 Geoff Parling, 4 Louis Deacon (c), 3 Dan Cole, 2 Tom Youngs, 1 Marcos Ayerza.
Replacements: 16 Rob Hawkins, 17 Logovi'i Mulipola, 18 Martin Castrogiovanni, 19 Ed Slater, 20 Thomas Waldrom, 21 Sam Harrison, 22 George Ford, 23 Matt Smith.
Venue: Liberty Stadium
Referee: John Lacey (Ireland)