CIS Insurance Cup holders Celtic have been knocked out this season's competition after a dramatic penalty shoot-out defeat to Falkirk at Parkhead.
Both clubs had to settle for a 1-1 draw after extra time before The Bairns triumphed 5-4 on penalties on Tuesday evening.
Bhoys boss Gordon Strachan made six changes to the side that claimed a dramatic late win over Hearts in the Scottish Premier League on Saturday, and the Old Firm club struggled to break John Hughes's side down.
The first half saw Falkirk survive two goal-line clearances, with Darren Barr blocking Shaun Maloney's strike, while Stephen O'Donnell knocked Jan vennegoor of Hesselink's header off the line.
The second half saw Falkirk create chances of their own, with Alan Gow forcing Celtic captain Gary Caldwell into a goal-line clearance of his own before Stokes hit the post for the visitors, as the match went to extra time.
Nine minutes into extra time, Maciej Zurawski broke the deadlock for Celtic when he headed home Vennegoor of Hesselink's cross.
The lead lasted just a minute, as Falkirk's highly-touted on-loan striker Anthony Stokes struck home to ultimately send the tie to a penalty shoot-out.
In the shoot-out, both clubs scored four penalties and missed two before Falkirk's Jack Ross scored his spot kick to put pressure on Celtic's Evander Sno to convert.
The Dutchman missed the target with his spot-kick, and The Bairns celebrated reaching the semi-finals with their travelling support.
Kilmarnock are also through to the semi-finals after seeing off SPL rivals Motherwell 3-2 at Rugby Park.
Frazer Wright gave Killie the lead after seven minutes with an indirect free-kick strike before The Well equalised from the penalty spot.
Wright went from hero to villain when he brought down David Clarkson in the Kilmarnock box before Richie Foran converted the spot kick on 25 minutes.
Wright then restored Kilmarnock's lead on the stroke of half time when he headed Peter Leven's long free kick home from six yards.
Maurice Malpas's side equalised again just before the hour mark, as Clarkson converted Steven McGarry's cross past Killie goalkeeper Graeme Smith at the back post for 2-2.
The scoreline lasted until the 71st minute, as Danny Invincible won the tie with a curling left-foot strike to send Jim Jefferies's side through.