Leinster's defence of the Pro12 title came to an end on Saturday as Ospreys clinched a top-four berth with a 31-23 win over Cardiff Blues.
Having seen Leinster lose 26-10 to Ulster on Friday, Ospreys knew that a win at the Millennium Stadium would secure a semi-final place, and they duly delivered thanks predominantly to 16 points from fly-half Dan Biggar.
Ospreys trailed 9-7 at the break but Biggar crossed four minutes after the restart for a try that he also converted, and then added the extras to two further scores as well as a penalty to seal a bonus-point success and end Leinster's hopes of back-to-back championships.
Glasgow Warriors, meanwhile, returned to the top of the table with a 31-13 bonus point victory at Connacht.
Two Jack Carty penalties put Connacht 6-0 to the good but a pair of first-half tries from wing Nikola Matawalu - sandwiched by a Stuart Hogg score - gave the visitors a commanding 19-6 lead at half-time.
Connacht threatened a comeback as an Aly Muldowney try narrowed thir deficit to six points, but Adam Ashe and Tommy Seymour each crossed to make sure of a straightforward win for the Warriors.
Glasgow hold a two-point advantage over Munster at the summit after the Irish side saw off struggling Treviso 30-19.
Flanker Tommy O'Donnell marked his 100th appearance for Munster by scoring one of three first-half tries for the hosts, with a converted penalty try and an Ian Keatley penalty seeing the three-time champions home in routine fashion.
Elsewhere, Scarlets boosted prospects of a place in next season's European Champions Cup by moving into the top six with a 29-10 bonus-point triumph over Newport Gwent Dragons.