Leicester will need to beat four-time European champions Toulouse at Welford Road next Sunday in their quest for a prized Heineken Cup quarter-final place after drawing 15-15 with Ospreys.
The Tigers lie two points behind the French heavyweights in Pool Two following an absorbing Liberty Stadium tussle that saw Ospreys substitute Jonathan Spratt score a 77th-minute try to deny Leicester victory.
The visitors looked to have done enough through quickfire second-half touchdowns from scrum-half Ben Youngs and wing Niall Morris after they trailed 10-3 for much of the contest after Ospreys posted a 34th-minute Joe Bearman touchdown.
Dan Biggar and his opposite number, Leicester's Toby Flood, each kicked a conversion and penalty, but the Ospreys would have won had Biggar not missed four penalties - three of them either hit the post or bar - and a late conversion.
It was rough justice on the Ospreys, who are now out of the competition for another season, yet Leicester summoned all their trademark resilience to secure two priceless points away from home that sets up a mouthwatering encounter in seven days' time.
Munster remain in the hunt for a place in the knockout stages after a laboured 26-17 win over a lacklustre Edinburgh side that only sprang to life in the final 10 minutes at Murrayfield.
A penalty try and a touchdown by Conor Murray plus 14 points from the boot of Ronan O'Gara sealed the victory for the visitors, while the home side's points came through two tries from Dougie Fife, both converted by Greig Laidlaw, who also landed a penalty.
The win leaves Munster in second place in Pool One on 15 points, three behind leaders Saracens and three ahead of Racing Metro.
Edinburgh remain bottom without a point.
In the day's other game Toulouse claimed a 35-14 bonus-point win over Benetton Treviso.
