Leinster easily secured the single point they needed to progress in the European Cup by beating the Ospreys 36-3.
The Irishmen were never challenged by a Welsh team ravaged by injury and further weakened on Friday night by the red-carding of Wales lock Ian Evans for stamping in the 20th minute. The decision by French referee Romain Poite, which seemed fully justified, nevertheless has severe implications for Wales, who play their first Six Nations match against Italy on 2 February.
Leinster led 17-3 at half-time with a penalty try and a burrowing touchdown by Cian Healy. They added another penalty try and scores by Jordi Murphy and Isaac Boss as the Ospreys put up a heroic but futile defence against a rather haphazard Leinster attack.
In the second Pool 1 match on Friday night, Northampton kept their hopes alive with a 13-3 win against Castres. They led 3-0 at half-time. South African Rory Kockott came off the bench to slot a long-range equaliser but Stephen Myler added another penalty and George Pisi secured the win with a minute to go by charging down a Kockott clearance.
Leinster join Ulster, Toulon, Toulouse, Clermont, Leicester and Munster in the knockout phase. Saracens will need a win against Connacht on Saturday to secure their place.
Saturday fixtures: Cardiff Blues vs Exeter, Glasgow vs Toulon, Saracens vs Connacht, Zebre vs Toulouse, Montpellier vs Benetton Treviso, Leicester vs Ulster.
Sunday fixtures: Scarlets vs Harlequins, Clermont Avergne vs Racing Metro, Munster vs Edinburgh, Perpignan vs Gloucester.
Photo: Michael Steele/Getty Images