Hearts to play Rangers & Aberdeen will face Hibs in semis
Hibernian 4-2 St Mirren - Tanser nets for visitors; Youan & Vente hit back; Baccus levels but Boyle nets twice
Ross County 1-2 Aberdeen - Shinnie with stunning 18-yard volley before Baldwin sent off for hosts; Sokler adds second after break before Turner pulls one back
Rangers 4-0 Livingston - Sima gives hosts controversial lead before Yilmaz adds second, De Lucas nets own goal & Jack scores
Rangers 2-0 Livingston
Kenny Miller
Former Rangers striker on BBC Sportsound
It's an incredible goal from Ridvan Yilmaz.
He travels 60 yards from well inside his own half.
Image source, SNS
Image source, SNS
Image source, SNSHibernian 3-2 St Mirren
Another five-goal thriller between Hibs and St Mirren, ye say?
This time, the Leith side are on the right end of a 3-2. But it isn't over yet...
Ridvan Yilmaz
What a run. What a finish!
Ridvan Yilmaz scores his first Rangers goal in style, picking up just inside his own half then racing towards goal and releasing a fierce drive past Shamal George from outside the box.
A much more comfortable position for the hosts just when Livingston were gaining a foothold.
Image source, BBC SportKyle Turner (pen)
Slobodan Rubezic downs Samuel as he races onto the ball and it's instantly awarded.
Second-half substitute Turner converts and gives County some last-gasp hope.
Kelle Roos had no chance as he is sent the wrong way by the former Partick Thistle man.
Image source, BBC SportMartin Boyle
This is a madness.
Fantastic build-up play from Hibs, they're so patient with Whittaker and Campbell involved along the way.
That man Boyle is there to crack the ball off the bar and into the net to round it off, too.
Image source, BBC SportHibernian 2-2 St Mirren
Kheredine Idessane
BBC Sport Scotland at Easter Road
Cracking equaliser from second-half substitute Keanu Baccus. An excellent first-time shot low past David Marshall into the corner.
This just after a triple substitution for Hibs with Paul Hanlon, Josh Campbell and 16-year-old Rory Whittaker entering the fray.
Some game here.
Image source, SNSRangers 1-0 Livingston
Allan Preston
Former St Johnstone defender on BBC Sportsound
Great play by Livingston, they are not out of this yet. They are starting to believe now.
Rangers 1-0 Livingston
Joel Nouble tries to emulate Abdallah Sima. He bustles his way past James Tavernier, who doesn't get the foul, and sees his shot turned out for a corner by Connor Goldson.
In comes the delivery and Luiyi de Lucas heads just wide.
Image source, SNSEster Sokler
Aberdeen are surely Hampden bound now.
Ester Sokler with his first Dons goal has likely finished this game off.
Leighton Clarkson curled in a lovely ball from Sokler to nudge in on the volley.
Image source, BBC SportKeanu Baccus
What a game at Easter Road!
That's against the run of play... Hibs have been tremendous in this second half.
Baccus has just been on over 10 minutes and he's made his mark in fine style.
Image source, BBC SportRangers 1-0 Livingston
Almost a second for Rangers and Abdallah Sima.
The forward smacks in a shot from tight angle on the left and Shamal George beats away. Sima then centres and the ball flies through a clutch of players out for a throw-in.
Rangers knock at the door again and James Tavernier sets up John Lundstram to shoot over.
Ross County 0-1 Aberdeen
Penalty shout for the Dons as Conor Randall clashes with Graeme Shinnie at the edge of the box.
Some pretty ardent claims from the visitors weren't interesting the referee whatsoever though as play continues.
A let off perhaps for Ross County as they chase an increasingly unlikely equaliser.
Rangers 1-0 Livingston
Kenny Miller
Former Rangers striker on BBC Sportsound
Rangers need to get back on the front foot. They really need to get that second goal to put it to bed.
Hibernian 2-1 St Mirren
Kheredine Idessane
BBC Sport Scotland at Easter Road
From 1-0 up and cruising to 2-1 down and chasing it, St Mirren have reached for the reinforcements.
From the bench come Alex Grieve, Keanu Baccus and Conor McMenamin, with Caolan Boyd-Munce, Mikael Mandron and Greg Kiltie hooked.
Ross County 0-1 Aberdeen
Tyrone Smith
BBC Scotland at Global Energy Stadium
Credit to Ross County - they are refusing to buckle, and are starting to grow into the game despite being a man down.
The hosts are starting to make life pretty awkward for the Dons, albeit they have yet to work Kelle Roos in the away goal.
Hibernian 2-1 St Mirren
Image source, SNSWill Fish heads on to Elie Youan to net Hibs' leveller
Image source, SNSA minute later, Dylan Vente finishes on the spin to turn the tie on its head
Hibernian 2-1 St Mirren
Don't know what Nick Montgomery said at half-time, but it's working.
St Mirren haven't had a sniff in the second half and fresh legs will be taking on the Buddies defence as Adam Le Fondre replaces Christian Doidge.
Rangers 1-0 Livingston
Rangers have made a change at half-time with Cyriel Dessers on in place of Kemar Roofe.
Rangers 1-0 Livingston
And we're now back up and running at Ibrox.
Ross County 0-1 Aberdeen
Duk and Jonny Hayes trot off.
Leighton Clarkson and Ryan Duncan are on for the last 35 minutes or so.
Little else of note happening in the Highlands as County push for a leveller.