As expected Leinster, Ospreys, Munster and Glasgow will contest the semi-finals of the RaboDirect PRO12 with Heineken Cup finalists Leinster squaring off against Glasgow while their provincial rivals Munster will play old foes Ospreys.
Leinster travelled to Rodney Parade and came away with a hard-fought 22-18 win with Ian Madigan in sparkling form with the boot - the out-half kicked five penalties and one conversion while Jack McGrath went over for Joe Schmidt's side's only try after 22 minutes.
Elsewhere, Munster ran out convincing 36-8 winners over Ulster in what was a repeat of the recent Heineken Cup quarter-final clash at Thomond Park.
The hosts put five tries on the board through Simon Zebo, Peter O'Mahony, Mike Sherry, Stephen Archer and Tommy O'Donnell against an under-strength Ulster outfit whose attention will now be firmly fixed on Twickenham on May 19.
At Firhill Stadium, Glasgow put Connacht to the sword and in the process booked their place in the last four thanks to an impressive 24-3 triumph which included tries from Dan van der Merwe and John Barclay.
Finally, Ospreys did what was required of them to make the semi-finals with Richard Fussell and Hanno Dirksen going over for the tries against Aironi at Stadio Zaffanella.