Biarritz Olympique backs coach Jack Isaac insists his side can't make the same mistakes against Toulouse as they did in last season's Heineken Cup final.
The Basque giants fell to an agonising 21-19 loss to Toulouse at Stade de France in last season's showpiece final.
But they are looking to make amends on Sunday when the two sides meet in the weekend's final quarter-final.
And Isaac has emphasised the importance of not falling into the same trap against the reigning European Champions.
"It's important that we master the basics and match them physically," said Isaac.
"In the final last year we didn't do that and we suffered in the physical battle. We have to make sure our backs aren't on the back foot.
"If Toulouse can get on the front foot again and build momentum they can be irresistible. We can't allow them to build confidence.
"We scored the only try of that match but it was too late and to be honest we had a few last-ditch tackles very close to our line."
Biarritz were also the victims of one of the season's biggest shocks, falling to a 28-27 defeat at the hands of Aironi in December. Isaac admits that game still haunts him but maintains the Basque club are a better team for the defeat.
"I've relived that game a thousand times and know it off by heart. We made a good start but just fell asleep and allowed the opponents to build confidence. But the three-quarters are expressing themselves better collectively this year."