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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Celtic 4-0 St Johnstone
It's a bit of a training exercise at Celtic Park, with the home side keeping possession and a broken looking St Johnstone defending at near walking pace.
Six minutes of normal time remaining for the visitors to endure.
Christophe Berra
That didn't take long.
Olly Lee's delivery is met by Christophe Berra and the Hearts captain powers his header past goalkeeper Andrew Leishman.
That's the defender's first goal of the season.
Image source, BBC SportAberdeen v Queen of the South (15:30)
Aberdeen make just one change from their midweek Premiership loss to Rangers, reverting back to the line-up that beat Hibs at Easter Road last weekend.
With centre-half Scott McKenna suspended, he drops out and striker Stevie May starts again.
Queen of the South make two changes from their 3-0 Championship defeat to Falkirk.
Former Don Nicky Low comes into midfield and Michael Doyle into defence. Out go winger Fraser Aird and on-loan Kilmarnock midfielder Iain Wilson.
Nicky Low: Death of his captain, glory at Aberdeen and dancing for Dobbie
Image source, SNSNicky Low, now at Queen of the South, won the League Cup with Aberdeen in 2014
Heart of Midlothian 0-0 Auchinleck Talbot
Uche Ikpeazu inches away from the opening goal.
The big striker canters into the box, right of goal, and his clipped shot is tipped just behind by Andrew Leishman.
Some of the Hearts fans were celebrating as the ball bobbled behind the net.
Heart of Midlothian 0-0 Auchinleck Talbot
A very early chance for Hearts talisman Steven Naismith.
Auchinleck fail to clear a corner and the Scotland attacker volleys over the bar from around 15 yards out.
Heart of Midlothian 0-0 Auchinleck Talbot
Kevin Clancy blows his whistle and we're off and running in Gorgie.
Hearts, eight-time Scottish Cup winners, out to book their place in the quarter-finals.
Auchinleck, though, have won their last 11 matches.
Image source, SNSThe village of Auchinleck has headed to Edinburgh
Celtic 4-0 St Johnstone
Is the departed Oliver Burke your man of the match? Or two-goal Scott Sinclair? Who has been St Johnstone's top man? Here's your chance to vote.
How did you rate the players in Celtic's Scottish Cup last-16 win over St Johnstone?
Read MoreHeart of Midlothian v Auchinleck Talbot (15:00)
The teams are out at Tynecastle, greeted by a very large crowd on a special day for Auchinleck.
Our reporter Brian McLauchlin reckons 1600 of the junior team's supporters have made the trip to Edinburgh.
Can they spring an almighty cup shock?
Celtic 4-0 St Johnstone
Jim Duffy
BBC Sportsound summariser
Quote MessageBurke has been terrific, his movement, going in behind, coming short, he gave those defenders an absolute nightmare. He's been instrumental for Celtic with another couple of assists
Celtic 4-0 St Johnstone
Maybe a worry for Celtic ahead of their Europa League game to come as Oliver Burke limps off to be replaced with fellow forward Timothy Weah.
Meanwhile, Saints bring off the injured Murray Davidson and on comes Ross Callachan in midfield.
Heart of Midlothian v Auchinleck Talbot (15:00)
Auchinleck boss Tommy Sloan makes a solitary change from his side's 7-0 thumping of Petershill in the West of Scotland Premiership.
Long-serving midfielder Dwayne Hyslop is promoted from the bench at the expense of Keir Samson.
The junior side have won their last 11 games. It would be a monumental shock if they made it 12 on the bounce in Gorgie.
Image source, SNSDwayne Hyslop will start for the junior side
Celtic 4-0 St Johnstone
St Johnstone midfielder Murray Davidson has had loads of injury problems in his career and is struggling again after colliding with team-mate Chris Kane as the striker barged into Scott Brown.
Celtic 4-0 St Johnstone
Celtic boss Brendan Rodgers responds by introducing more attacking threat.
Fit-again striker Odsonne Edouard is on for midfielder Ryan Christie.
Celtic 4-0 St Johnstone
It is damage limitation now for St Johnstone manager Tommy Wright.
He sends on Niall Keown, the centre-half on loan from Partick Thistle, for his debut in place of winger Matty Kennedy.
Celtic 4-0 St Johnstone
Paul Hartley
Former Celtic and Scotland midfielder on BBC Radio Scotland
Quote MessageA lot of players would look at that and think I can't get that. Burke was nowhere near favourite to get that ball, 15 yards behind, put on the after-burners and plays a perfect ball across the box for Sinclair. Another tap-in. Absolutely sensational from Burke and Sinclair to make those runs all the time
Heart of Midlothian v Auchinleck Talbot (15:00)
Image source, BBC SportHeart of Midlothian: Doyle, Smith, Souttar, Berra, Mitchell, Djoum, Lee, Clare, Naismith, Maclean, Ikpeazu.
Substitutes: Zlamal, Shaughnessy, Bozanic, Mulraney, Vanecek, Keena, Morrison.
Auchinleck Talbot: Leishman, Lyle, McPherson, McCracken, Armstrong, Pope, White, Hyslop, S Wilson, Glasgow, G Wilson.
Substitutes: Hewitt, Samson, McIlroy, Kemp, Shankland, Waite, Harvey.
Image source, BBC SportCeltic 4-0 St Johnstone
Paul Hartley
Former Celtic and Scotland midfielder on BBC Radio Scotland
Quote MessageGreat play from Jonny Hayes driving with the ball. That's the Jonny Hayes of old at Aberdeen. It's a great weighted pass to Forrest and a nice finish there
Scott Sinclair
Another goal burst from Celtic and it's all over.
Oliver Burke's pace again tears apart the visiting defence and the on-loan West Brom winger rolls a cross into the six-yard box and Scott Sinclair taps in his second of the day.
Image source, SNSJames Forrest
Just as St Johnstone were showing some promise, Celtic just about kill off their hopes of a comeback.
Jonny Hayes skips past a couple of challenges and sets up James Forrest.
The winger scuffs his shot, but it goes between the legs of goalkeeper Zander Clark.
Celtic 2-0 St Johnstone
St Johnstone's high press has its dangers and Oliver Burke speeds clear but shoots straight at goalkeeper Zander Clark.