FT Aberdeen 4-1 Queen of the South - McGinn, Considine, Cosgrove (2) for hosts; Dobbie had levelled with stunner
FT Hearts 4-0 Auchinleck Talbot - Berra, Mitchell, Maclean & Keena knock out juniors
FT Celtic 5-0 St Johnstone - Sinclair hat trick, Brown stunner & Forrest goal put holders into quarter-finals
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Heart of Midlothian 3-0 Auchinleck Talbot
Out of nowhere, Auchinleck come agonisingly close to pulling one back.
Jamie Glasgow, the junior side's number 10, is played in behind the home defence, but his attempted lob bounces the wrong side of Colin Doyle's post with the goalkeeper struggling and the midfielder misses a chance for a 13th goal of the season.
Heart of Midlothian 3-0 Auchinleck Talbot
Julie Fleeting
Former Scotland striker on BBC Sportsound
Quote MessageHearts are very patient in their build-up and they're using all their players. The movement they've got to drag the Auchinleck players out is causing them problems
Heart of Midlothian 3-0 Auchinleck Talbot
Allan Preston
BBC Scotland summariser
Quote MessageThe desire Hearts have shown in that opening 35 minutes is incredible. Yes, it's a junior side, but they've shown them all the respect. Taken things quickly, not let the junior side settle at all
Aberdeen 0-0 Queen of the South
A great chance for Aberdeen to take the lead.
On-loan Derby County left-back Max Lowe's cross finds Shay Logan at the back post, but the unmarked right-back heads wastefully over from 10 yards.
Steven MacLean
Hearts net a well-crafted third goal.
Demetri Mitchell, scorer of the second, receives the ball from a short corner and clips a low ball across the face of goal.
Steven MacLean simply has to side-foot it into the net from point-blank range.
This could get very ugly for Talbot...
Image source, BBC SportHeart of Midlothian 2-0 Auchinleck Talbot
Fantastic stop from Andrew Leishman prevents Talbot falling further behind.
Steven Maclean is set free in the box by a penetrating through ball.
He tees the shot up on his right foot, but the goalkeeper dives to his right to palm it away.
Aberdeen 0-0 Queen of the South
They are under way at a sun-drenched Pittodrie.
The Dons are dominating the ball in the early stages.
Heart of Midlothian 2-0 Auchinleck Talbot
Allan Preston
BBC Scotland summariser
Quote MessageGood sustained pressure from Hearts, going from right to left. Mitchell doesn't strike it well at all, not a lot of power or pace on it, but it's found its way into the net and it's a long way back for Talbot now
Demetri Mitchell
That might well be that. No sign of a cup shock at Tynecastle, with the Premiership hosts utterly dominant and grabbing a deserved - if scrappy - second goal.
Demetri Mitchell collects the ball on the edge of the box, cuts on to his right foot, and the on-loan Manchester United wide man scuffs a low, bobbling shot beyond Andrew Leishman.
It wasn't struck with great power and may have taken a nick off a Talbot defender en route to the bottom corner.
Image source, BBC SportHeart of Midlothian 1-0 Auchinleck Talbot
Allan Preston
BBC Scotland summariser
Quote MessageIt's been very professional so far from Hearts, got that early Berra goal, could be a couple more. Been slack a couple of times though and, while it's 1-0, Talbot will believe they still have got a chance
Heart of Midlothian 0-0 Auchinleck Talbot
This is only Uche Ikpeazu's second appearance and first start since returning from an October foot injury.
Albeit against junior opposition, the big striker looks impressive, using his power and awareness to carve out a few decent chances for himself.
Aberdeen v Queen of the South (15:30)
Queen of the South reached their first-ever Scottish Cup final by winning a seven-goal thriller against Aberdeen in 2008.
The two clubs have met since then, Aberdeen winning through after a replay in 2012.
Can the Championship side spring an upset today?
Image source, SNSStephen Dobbie (right) chases Aberdeen's Alan Maybury
FT: Celtic 5-0 St Johnstone
Paul Hartley
Former Celtic and Scotland midfielder on BBC Radio Scotland
Quote MessageCeltic never let up their intensity and quality. Two-nil down after nine minutes, you're chasing it and it was damage limitation for St Johnstone
Aberdeen v Queen of the South (15:30)
Image source, BBC SportAberdeen starting XI
Aberdeen: Lewis, Logan, Hoban, Considine, Lowe, Shinnie, Ferguson, Mackay-Steven, Stewart, May, Cosgrove
Substitutes: Cerny, Gleeson, Wilson, McGinn, Devlin, Ball, McLennan
Queen of the South: Martin, Mercer, Marshall, Fordyce, Doyle, Stirling, Jacobs, Dobbie, Low, Dykes, Maguire
Substitutes: Leighfield, Aird, McGrath, Murray, Irving
QOTS starting XI.
Celtic 5-0 St Johnstone
Jim Duffy
BBC Sportsound summariser
Quote MessageI never understand the criticism about Sinclair. He's a winger who is actually a poacher, he sniffs around that six-yard line. People say he's lucky, but he's not. He's in the right area and has calmness and composure. Another hat-trick - outstanding for a wide player
Celtic 4-0 St Johnstone
Can you see past Scott Sinclair as Celtic's top performer in their win over St Johnstone? Who was most disappointing?
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Read MoreCeltic march on in dominant fashion in search of retaining the Scottish Cup after completing a fifth win of the season over St Johnstone.
Scott Sinclair is the star with a hat-trick, with captain Scott Brown and James Forrest chipping in with one apiece.
Image source, SNSScott Sinclair scored a hat-trick against St Johnstone
Heart of Midlothian 1-0 Auchinleck Talbot
A sniff for the junior side as top scorer Graham Wilson latches on to a William Lyle long ball, but sclaffs his effort from a tight angle.
Moments later, Hearts work their way downfield, and Uche Ikpeazu swivels and shoots straight at Andrew Leishman from close range.
Scott Sinclair
Scott Sinclair rubs in the misery by completing his hat-trick - his 16th of the season.
An Odsonne Edouard shot takes a deflection and, although the winger looks to be slightly offside, he turns Niall Keown inside out before firing past goalkeeper Zander Clark.
Image source, SNSCeltic 4-0 St Johnstone
Jim Duffy
BBC Sportsound summariser
Quote MessageSaints just want this game to be over, they've wanted that since about 10 minutes into the game I think. Celtic have been terrific throughout the game and they've kept at it, but St Johnstone have hardly had a sniff