Ulster head coach Dan McFarland believes his side let slip a golden opportunity to win in France as they slipped to a 29-13 defeat to Clermont Auvergne.
Defeat leaves Ulster needing to beat Bath in the final round of pool fixtures next weekend to be sure of a place in the quarter-finals of the Heineken Champions Cup.
Tries from Alivereti Raka and George Moala helped secure victory for the French side, while John Cooney scored all of Ulster's points with a try, conversion and a penalty.
"We are bitterly disappointed," said McFarland.
"It was a game we had control of in the first half and we didn't make our pressure pay when we should have done. If you are going to be good enough to win in Clermont and they are down to 14 men and you kick to the corner and you can't score tries, then you aren't a good enough team to win in Clermont.
"If we took advantage of those opportunities and score, which we are capable of doing, then we'd have had a much better chance of going on to win the game."
"We have to win next week and we have to get a minimum of 20 points," said McFarland.
"There were a couple of occasions in that first-half where we didn't execute as well as we needed to to get the points on the board we needed. It is really frustrating because they (Clermont) cheat at the scrum, let's face it.
"Sometimes they hit hard, sometimes they hit soft and it's really difficult to deal with, but that doesn't negate the fact that we got pushed backwards."