"They will be a team with nothing to lose when they come to San Sebastian in the quarter-final. I always feel a danger with my team when the situation seems ideal for us," said Lagisquet.
"It will be a new game for both sides in the quarter-final and we will certainly respect Northampton.
"If you are over confident then you can find yourself in trouble.
"We aren't at the same level in attack as we were last season, but we are building our confidence. With greater confidence we will become a better side.
"When we went to Ulster and won last season it gave the team a lot of self belief. Perhaps we needed to go down to 13 men in this game to fins our true competitive spirit.
"I have seen so many intense matches in the Heineken Cup over the last weekend. The standard continues to rise.
"I love this tournament and I hope that one day Biarritz will Toulouse and Brive as French teams who have won the title."