Rangers summoned up the energy to become extra time heroes for the second time in four days as they turned Treble busters against rivals Celtic in a Hampden epic.
Giovanni van Bronckhorst's men should have been out on their feet but showed incredible character to come from behind to book their place in the Scottish Cup Final with a 2-1 win.
Fashion Sakala is a player many have doubted to have the quality needed to make it at Ibrox but the Zambian was the super sub as he grabbed the winner in a sensational game.
Ange Postecoglou's men could have few complaints as they were outplayed against their rivals who were forced to go to the end following their midweek Europa League quarter final win over Braga.
It's Van Bronckhorst's first win over Celtic as a manager after back to back defeats as he looks to win the trophy for the club for the first time since 2009 to end Postecoglou's clean sweep hopes.
Greg Taylor – released by Rangers as a kid – fired Celtic into a second half lead and that looked to have sapped any remaining energy out of the Ibrox side following their extra time midweek exertions.
But Van Bronckhorst’s men somehow managed to find the energy as the fresh legs of substitute Scott Arfield grabbed a leveller and force extra time for Rangers for the second time in four days before Sakala netted.
The atmosphere was electric and Rangers, just as they did in the recent league meeting at Ibrox started quickly, with the first real chance.
John Lundstram made a brilliant challenge to pick Reo Hatate’s pocket and threaded a pass through to Ryan Kent but Callum McGregor got back to make an excellent challenge.
Jota then headed just off target at the other end from Liel Abada’s cross as the game started at a fast tempo.
Kemar Roofe then flashed a shot wide as the game ebbed and flowed with a goal the only thing missing.
Rangers looked the more likely to score and Carl Starfelt had to make amends for initially conceding possession as the Swede headed Roofe’s effort clear before Joe Aribo’s effort from the rebound was straight into Joe Hart’s arms.
Lundstram came closest to breaking the deadlock five minutes before the break with the midfield curling a brilliant left foot effort off the post.
Gers suffered an injury blow after that when Aaron Ramsey limped off with what looked like a hamstring issue as Scott Wright replaced him.
The Light Blues continued to look the better side after the restart but Hatate had a glorious chance to score but pulled his shot wide.
Kent then fired a whisker wide with Hart scrambling low to his left before Postecoglou made a double change with Liel Abada - who pulled up - going off along with the ineffective Tom Rogic as Kyogo and Matt O’Riley were introduced.
That gave the Hoops renewed energy and they soon had that vital breakthrough as they caught Rangers out.
A quick free kick - one Rangers disputed for a foul by Roofe on Cameron Carter-Vickers - was played to McGregor who prodded the ball into Taylor’s path and the full back shot low into the corner with the ball taking a slight deflection off Bassey.
Carver-Vickers should then have added to his recent derby winner as he crashed a shot off the crossbar when the ball broke kindly to the American from a corner.
Gers looked to be flagging at that point but somehow they summoned the energy to get themselves level.
Arfield had only been on the pitch a couple of minutes - a double substitution with Steven Davis also on - and his fresh legs helped get his side back into it.
Goldson played a brilliant long ball to Tavernier and his cross into the box was laid off by Roofe into Arfield’s path and he fired past Hart.
That ensured another 30 minutes of an enthralling semi final as these two slugged it out.
Rangers came agonisingly close to scoring when Tavernier's angled shot came off the post and extra time substitute Sakala's acrobatic effort from the rebound bounced off the crossbar.
But it was the Zambian who found the net with five minutes of the 120 remaining.
Bassey stormed down the left wing and Sakala showed more determination than Starfelt to stab home.
Here's 5 talking points from a Hampden epic...
Running empty but full of spirit
These Rangers players have been forced to go to the well so many times with their run to the Europa League semi final.
And when they went a goal down you would have expected that to be the end of their challenge as Celtic were in the ascendency.
But they managed to dig deep and conjure up an unlikely equaliser for which they deserve immense credit.
Midfield master
John Lundstram’s career took a while to get going and few fans would have cared if he had moved on in January.
But the former Sheffield United has totally turned things around at Ibrox and was a colossus in the engine room for Giovanni van Bronckhorst.
Lundstram was everywhere for Rangers, helping in attack and getting back to win vital defensive tackles.
Gers bury Hampden hoodoo as Celtic’s incredible run ends
There was a real contrast in fortunes before this game for both sides at the National Stadium.
Celtic had won 17 games in a row going into the semi final, scoring 40 goals and conceding just 10.
Their rivals had a miserable record in Mount Florida with just two wins from a dozen outings - and one of those was that penalty shoot out victory over the Hoops in 2016.
That was a run that started after their 2011 League Cup win so there was a psychological barrier to overcome as well as Celtic’s own formidable record.
Aaron agony
Aaron Ramsey’s fitness record was a concern before the Welsh superstar moved to Ibrox on loan from Juventus.
And the midfielder simply hasn’t featured enough since his signing with another spell on the sidelines looking likely.
The 31-year-old looked like he was finally set for a run in the starting XI after featuring against Braga and then this Hampden clash.
But he couldn’t even make it until half time as he limped off just before the break which is a real blow with the Europa League semi-final on the horizon.
Super spectacle
There is nothing to beat the Old Firm rivalry and with the reduction in the away allocation for league games there has been something missing.
But for the two fierce foes to go head to head with a 50-50 split at Hampden it was a reminder of what an occasion this is and they served up a classic.
The atmosphere was electric ahead of kick off with smoke filling the Mount Florida air as the teams came out.
There is an ugly side to the derby at times as was the case with the bottle thrown onto the pitch at Ibrox recently but there can be no denying it’s one of best fixtures in world football.
