the saints , who sit 10 points clear at the summit of the aviva premiership , exited europe at the quarter-final stage after being routed four tries to one at the stade marcel-michelin .
the result had been decided by half-time as clermont , employing a mixture of forward supremacy and three-quarter devilry , amassed an unassailable 27-0 lead .
northampton captain dylan hartley leads his team off the pitch after crushing defeat .