Ulster earned a home semi-final against the Scarlets by seeing off Cardiff Blues 37-13 at a wet Ravenhill to finish top of the RaboDirect PRO12 table.
Two second-half tries from Andrew Trimble and a late score for 100-cap man Robbie Diack set Ulster on their way after Mark Anscombe's side had trailed 13-10 at half-time against a Blues effort which petered out in the second half.
Ruan Pienaar scored 22 of Ulster's total with a first-half try, along with four conversions and penalties on a night when Chris Henry also played for the 100th time for his club.
Glasgow Warriors missed out on a home semi-final, but tries from DTH van der Merwe and British and Irish Lions call-up Sean Maitland saw the Scottish side make the play-offs on the back of a 17-point win over Connacht.
On a windy night in the west of Ireland, Connacht were hoping to provide a winning send-off for departing head coach Eric Elwood, with the match also marking the final outings for the province of Johnny O'Connor, Adrian Flavin and Leinster-bound Mike McCarthy.
However, a Ruaridh Jackson penalty was added by a Van der Merwe try as the visitors established a 10-3 half-time advantage with Dan Parks nailing a late penalty for Connacht.
Elwood's charges battled bravely on the restart with the wind at their backs, but the benefit of a strong replacements bench was vital for Glasgow as five points from the boot of another Lion, Stuart Hogg, allied to Maitland's 70th-minute effort, eased them over the line.
The Scarlets crashed to an embarrassing four tries to one defeat to Treviso at Parc y Scarlets but still managed to book their place in the end of season play-offs.
They sealed a semi-final shot against Ulster in Ravenhill next Friday after the Ospreys went down 37-19 in Leinster.