O'Gara's La Rochelle hammer Bordeaux in away leg

La Rochelle's South African wing Raymond Rhule (L) scores a try during the European Rugby Champions Cup match agaiinst Bordeaux-Belges at the Chaban-Delmas stadium in Bordeaux, (Photo by Thibaud Moritz/AFP via Getty Images)

An all-Top 14 clash in the Heineken Champions Cup defied domestic form as Ronan O'Gara's La Rochelle prevailed 31-13 at Bordeaux.

Five tries lit up a lively last-16 first leg at Stade Chaban-Delmas that saw La Rochelle pull away in the third quarter.