Celtic booked their place in the last four as Anthony Stokes' goal gave them victory against St Mirren in Paisley.
Stand-in Hoops skipper Joe Ledley opened the scoring in the fifth minute with a header before a mistake by Parkhead left-back Emilio Izaguirre in the 13th minute allowed Esmael Goncalves an easy chance to level.
However, Stokes restored the visitors' lead in the 21st minute with a close-range header and at the end of a decent game it was enough to put Neil Lennon's side into Monday's draw at Hampden.
Celtic got the revenge they wanted following their defeat the Buddies in the Scottish Communities League Cup semi-final at Hampden in January and will be boosted ahead of the second leg of their Champions League last-16 clash with Juventus on Wednesday night.
Falkirk joined the Bhoys in the last four with a 2-1 victory over Hamilton at New Douglas Park.
Blair Alston struck just before half-time to give the Bairns the lead against the run of play and he doubled their lead with a stunning effort from the edge of the box after 71 minutes.
Substitute Andy Ryan pulled one back for the hosts however they were unable to grab a leveller in the closing stages.
A disappointing afternoon for Billy Reid's side was completed when Jonathan Page was sent-off in injury-time.