Next weekend’s semi-final clashes will pit Lansdowne against fourth-placed Cork Constitution, and Clontarf will host third-ranked Young Munster at Castle Avenue.
With top-scoring winger Daniel McEvoy notching his 11th league try, Lansdowne finished top on scoring difference after a 40-17 bonus-point dismissal of lowly Garryowen, who will host Old Wesley in a play-off on Sunday.
Former Ireland U20 international Conor O’Brien touched down twice in Clontarf’s action-packed 37-28 bonus-point win over UCD, while backs Ned Hodson and Michael Clune bagged braces as Cork Con got the better of St Mary’s (34-27).
Dublin University clawed clear of the relegation zone with Tim Maupin’s stunning last-minute try, which started in their own 22, earning them a 27-25 victory over Terenure College.
Munster centre Dan Goggin had two tries in Young Munster’s 33-12 bonus-point success at relegated Old Belvedere. Teenage out-half Alan Tynan contributed 13 points, including a first-half try.
Meanwhile, new Division 1B champions Buccaneers hammered Ballynahinch 40-10 at Dubarry Park. No 8 and captain Kolo Kiripati kicked a conversion in his final game for the club and prolific winger Jordan Conroy scored his 18th try of a stellar campaign.
Rodger McBurney’s first-half try guided Ballymena to a 13-10 home win over Shannon and Division 1B safety, while the losing bonus point ensured an eight-place finish for the Limerick men.
Naas relegated Galwegians with a 27-16 defeat in Glenina, Johne Murphy’s side securing a second-place finish and a home play-off against UL Bohemians.
A second-half brace from Paul Harte saw Old Wesley defeat UCC 19-5 and tee up a play-off trip to Dooradoyle, while Barry Keeshan kicked 11 points as relegation-threatened Dolphin upset UL 16-10. David Corkery’s charges will host Malone in the play-offs.