Ross County stunned holders Celtic with a 3-1 victory at Hampden to book a place in the League Cup final against Hibernian.
Celtic made a blistering start to a pulsating encounter and took the lead in the opening minute when Gary Mackay-Steven tapped home.
But the complexion of the match changed completely soon after when Efe Ambrose was sent off for denying Alex Schalk a goalscoring opportunity and Martin Woods converted from the penalty spot.
County took the lead three minutes after the break when Paul Quinn, making his first start since returning from Aberdeen, headed home from close range.
Alex Schalk put the Staggies 3-1 in front after 63 minutes before Leigh Griffiths missed a penalty as Celtic chased a way back into the match.
County held on to earn a place in the final against Championship side Hibernian on March 13.
Paul Quinn, who joined the Staggies from the Dons earlier in the week, came straight into the Ross County side as Jim McIntyre made three changes to the team that defeated Motherwell 2-1 last week.
Stewart Murdoch and Woods also started with Brian Graham, Jonathan Franks and Scott Boyd all dropping to the bench.
Celtic made one change with Belgian international Dedryck Boyata stepping in to replace the absent Jozo Simunovic, while captain Scott Brown was fit enough to join new signing Erik Sviatchenko on the bench.
It was a disastrous start for County as Celtic raced into an early lead after only 28 seconds.
Leigh Griffiths was afforded too much space to latch onto a Callum McGregor pass and unselfishly laid the ball across goal for Mackay-Steven to tap home the opening goal.
The Staggies were shell-shocked and almost conceded a second four minutes later when Efe Ambrose met a McGregor corner only for his downward header to be hacked off the line by the handily positioned Richard Foster.
The action-packed start to proceedings continued with Alex Schalk, the surprise lone forward for County, drawing an excellent stop from Craig Gordon with a powerful drive from the edge of the area.
More drama was to follow as County were handed an unexpected lifeline and they took full advantage.
Efe Ambrose was caught badly out of position as Schalk sped on to a Woods pass that was cleverly dummied by Jackson Irvine. The Nigerian defender clipped the heels of the Dutchman as he steadied himself to pull the trigger giving referee Craig Thomson no option but to point to the spot and produce a red card.
Woods made no mistake from the spot, sending Gordon the wrong way, as County restored parity.
McGregor was the unfortunate Celt to be sacrificed as Sviatchenko made a much earlier than anticipated debut as a result of Ambrose’s expulsion.
The Hoops almost regained the initiative five minutes before the break but Staggies goalkeeper Scott Fox displayed great bravery to save at the feet of Nir Bitton and Sviatchenko.
But, three minutes after the break, County took the lead from a cleverly-worked corner kick.
Woods’ back-post delivery found Davies who headed the ball back across goal for Quinn to nod home.
It got even better for County after 63 minutes when Woods, enjoying an excellent game, picked out Schalk with another clever pass and the Dutchman blasted the ball into the roof of the net.
But Celtic were handed a chance to pull a goal back with 13 minutes remaining when Staggies substitute Brian Graham handled in the box but Griffiths’ penalty was well saved by Fox.
County almost grabbed a fourth with 10 minutes remaining but Irvine’s effort was well saved by Gordon.
At the other end, Fox made an excellent instinctive stop to deny Griffiths as County held on for a memorable win.