Leicester Tigers claimed a first leg away win at Clermont Auvergne to take a stride towards the Heineken Champions Cup quarter-finals.
After an early Clermont try, Ellis Genge and Julian Montoya ground their way over to make it 10-10 at half-time.
Jack van Poortvliet and Hosea Saumaki crossed as the Tigers turned the screw, moving 12 points clear after the break.
Guy Porter's red card did not derail Leicester, with Harry Potter added a fifth try as Clermont lost discipline.
Leicester's dominance despite depleted numbers, combined with their form – this was their 25th win in 29 matches in all competitions this season – makes them hot favourites to meet either Leinster or Connacht in the last eight.
The teams meet again at Welford Road next Saturday with aggregate scores over the two matches deciding which progresses.
