Dylan Hartley has admitted that Northampton Saints were "caught cold" early on in their 37-5 Champions Cup quarter-final defeat against Clermont Auvergne.
The Saints were blown away as they conceding three tries and 27 points prior to the interval, before the French outfit made sure of a place in the last four with another try from man-of-the-match Nick Abendanon.
However, England hooker Hartley believes that early errors from Northampton helped to gift Clermont their victory.
"They are a quality outfit and, while no-one is invincible, after today they will take some stopping," he told Sky Sports.
"We did not get a foothold early on and after that compounded things with error after error.
"They were unbelievable. We got caught cold and their steamroller just kept on going and going."
Clermont will now meet the winner of Sunday's clash between Racing Metro and Saracens in the semi-final.
