Leicester Tigers revived their hopes of a Premiership Rugby Cup semi-final with a 41-26 home win over London Irish at Welford Road.
The Tigers will qualify as Pool B winners if Newcastle fail to beat Northampton on Wednesday.
Irish had already secured their place in the last four, but six Tigers tries helped end their 100% record.
England U20s star Henry Arundell gave Irish an early lead in the cross-group game at Leicester, as they looked to make it four wins out of four, before Bryce Hegarty levelled the score for the hosts.
Lucas Brooke then drove over the line for the Pool C winners, but the Tigers again responded, this time through Hosea Saumaki.
Juan Pablo Socino scored right before half-time to give Leicester the lead for the first time in the match before Sean Jansen added his first Tigers try early in the second half.
Full-back Hegarty scored and converted his second of the night before Philip Cokanasiga scored twice for Irish either side of a Charlie Clare touchdown.
Newcastle will almost certainly need a bonus-point victory against Northampton to displace Leicester at the top of Pool B, given the Tigers' vastly superior points difference.
Olly Robinson said: βIt was a fairly inexperienced squad but it was awesome getting a win against a side that were unbeaten coming into the game.
βWe've won by 20 points and we're a bit frustrated, so it's a really good sign for us that we can come away from a game where we've won but still frustrated by certain things.β Β
Referee: Hamish Smales
Tigers: Hegarty, Browning, Murimurivalu, Socino, Saumaki, Lancaster, Edwards; van Wyk, Clare, Hurd, Agbongbon, Chessum, Ilione, Robinson, Jansen
Subs: Cowan-Dickie, Richardson, Hoyt, Carnduff, Koroiyadi, Law, Woodward, Cusick
Irish: Arundell, Redmond, Joseph, Cokanasiga, Dykes, Reid, O'Sullivan; Dell, Willemse, Parker, Cunningham-South, Cooke, Donnell, Brooke, Smart
Subs: McElroy, Gigena, Green, Munga, Atkins, Englefield, Atkins, Harmes
Written by Ben Jaycock