Ulster fly-half Paddy Jackson admitted relief was the over-riding emotion as Ruan Pienaar's last-gasp try sealed a bonus-point win over Castres Olympique.
Last season's beaten Heineken Cup finalists started the new campaign with a 41-17 success at Ravenhill but they looked like missing out on maximum points until Pienaar's late intervention.
The South African star sliced through from halfway as Ulster attacked from deep in their own territory with the final play of an entertaining encounter in a group that also features Northampton Saints and Glasgow Warriors.
And with bonus points so often key to quarter-final qualification, Jackson says his replacement half-back's contribution could be crucial come January.
"If we hadn't got the bonus point it would have been a glum changing room," said Jackson, who kicked 21 points and missed the posts just the once.
"We need every point we can get to get through to the knockout stages again.
"When we were defending late on, I was just running around looking for an interception but Ruan got there in the end so we're very relieved.
"We tried to throw the ball wide but their defence wasn't as soft as we perhaps thought it was going to be to the touchline.
"The last half an hour was very scrappy and a real slugging match. I think they were trying to stop us from getting the bonus point but we're very happy to have got it."
