Ulster’s hopes of qualifying for the Champions Cup quarter-finals have received a boost after Wasps beat La Rochelle at the Ricoh Arena.
The result means that Ulster's destiny is now in their own hands: two wins from their two remaining games, while stopping the French side claiming a bonus point when they meet in the next round on 12 January, it would be enough to top Pool 1.
The Top 14 side, who had taken maximum points from their three games to date, still top the table but the 21-3 loss means that they remain just two points ahead of Les Kiss’ team.
Wasps, meanwhile, move to 10 points, three behind Ulster, but failed to pick up a bonus point in the victory.
La Rochelle will still be favourites to top the group but defeat in Ulster without a bonus point would change the shape of the pool.
La Rochelle host out-of-contention Harlequins in round six but should Ulster, who beat Quins 52-24 on Friday, take four points off them it will set up a fascinating clash away to Wasps, where a win would see Ulster finish top.
"We probably still need another six points [to top the group]," La Rochelle out-half Brock James said after the defeat to Wasps.
"We’re going to need a win at least at home. A win at Ulster? It’s not an easy thing to do.
"We’re playing without a complex and we’re trying to win everywhere we go."
Wasps could still be in contention on the final day but must target five points away at Quins in the next round and, beat Ulster at home on 19 January and then hope that Harlequins can pull off an almighty shock in France.
La Rochelle beat Ulster 41-17 in round 2.
It was Elliot Daly who led the way as Wasps avenged their 49-29 hammering at La Rochelle last weekend but the game was a far cry from last week's try-scoring extravaganza in France.
The home pack shaded a titanic forward battle as the French failed to come to terms with the murky conditions until the final quarter and could only manage a penalty from James in response to Wasps' three tries.
A late effort from Tom Cruse added to Daly's pair of tries, with Daly converting two and Danny Cipriani one.
Wasps director of rugby Dai Young said: "If we can win our two games we have a chance of squeaking through as we have given ourselves a fighting chance.
"We possibly missed out on a bonus point today as we controlled the match but not the scoreboard and didn't turn our pressure into points, especially in the first half."
