Scott Sinclair scores twice from close range for Celtic after being denied from the spot
Timothy Weah marks debut with goal to make it three for holders
10-man St Mirren come from two goals down to beat Alloa
Mark McGuigan's header earns Stenhousemuir a draw at Aberdeen
Ross County hold on as Brian Graham's double edges out Motherwell
McCracken header gives Junior side Auchinleck famous win
Craig Reid (own goal)
Aaron Doran delivers a threatening cross and poor Craig Reid can only divert it into his own net.
Caley Thistle are cruising into the fifth round.
Cody Cooke
St Mirren were looking well out of the game but Cody Cooke gives them hope from close range.
Kilmarnock 1-0 Forfar Athletic
Kenny Crawford
BBC Sport Scotland at Rugby Park
Killie’s Iain Wilson returned to the starting XI and has impressed as stand-in right-back and nearly creats a goal for Greg Kiltie.
Lewis Vaughan (pen)
Dunfermline had been on top after the break despite being down to 10 men but fall behind to a controversial penalty.
Chris Duggan is pulled up for a bit of wrestling and Lewis Vaughan scores from the spot.
Motherwell 0-2 Ross County
Martin Dowden
BBC Sport Scotland at Fir Park
Ross County are in complete control now thanks to Brian Graham’s double. Once again, it was Declan McManus who delivered a drilled low cross that Graham smashed home from close range.
Motherwell were furious though that Gboly Ariyibi was not awarded a foul in the build up, something we may hear more of post-match.
There has been nothing to suggest Motherwell have two goals in them this afternoon. They need to move up a couple of gears at least.
St Johnstone 2-0 Hamilton Academical
Chris Kane heads narrowly over as St Johnstone chase a third goal against Hamilton.
No sign of a comeback from the visitors at this stage.
Brian Graham
What a result this could be for County. Just a few minutes after Graham put the visitors ahead, he doubles their lead. Poor defending allows the big striker to get across his man and crash home a drilled cross.
It is all too easy for the Championship side. Motherwell haven't been at the races today. A big 30 minutes now for the Steelmen.
Motherwell 0-1 Ross County
Martin Dowden
BBC Sport Scotland Fir Park
On the balance of chances, it would be hard to argue against County being ahead.
They’ve looked threatening when going forward - in direct contrast to Motherwell, who have offered little in the final third.
Brian Graham’s goal was all about the delivery from Declan McManus, inch perfect for the big striker to nod home.
Ross McCormack was replaced at half-time, clearly needing matches to get up to speed, but it just wasn’t working for the home side and that trend has continued so far in the second.
A lot of work ahead for Stephen Robinson’s side if they’re to get back into this.
Raith Rovers 0-0 Dunfermline Athletic
Dunfermline centre-half Lee Ashcroft is sent off as he pulls down Chris Duggan as the Rovers man is through on goal.
The Fife derby could be turning for the worst for the Championship side against their League One hosts.
PJ Crossan
Any nerves at Firhill? PJ Crossan has pulled one back for the visitors with a fine strike past Conor Hazard.
Brian Graham
The Championship leaders are in front at Fir Park as Brian Graham throws himself at a diving header.
Daryl Horgan
Daryl Horgan scores his second of the game, finishing off from a Steven Whittaker cross after a quick counter-attack.
Joe Cardle
Former Dunfermline winger Joe Cardle looks to have eased the pressure on Championship strugglers Thistle as he fires them into a two-goal lead shortly after the break.
Ross County 0-0 Motherwell
Ross McCormack's debut (sort of) at Motherwell has lasted just 45 minutes. The on-loan Aston Villa striker, back for a third spell at Fir Park, was a surprise inclusion in Stephen Robinson's starting XI but has been replaced at the break with Curtis Main.
HT: Dundee 1-1 Queen of the South
Stephen Dobbie has now found the net 33 times this season.
But the veteran Queens striker's opener has been cancelled out by Jesse Curran's reply for the Premiership side.
Image source, SNSHT: Aberdeen 1-0 Stenhousemuir
Aberdeen are another Premiership side who have only a narrow lead against lower league opposition.
Max Lowe has marked his return to Pittodrie on loan from Derby County with the goal.
Image source, SNSHT: St Mirren 0-2 Alloa Athletic
St Mirren have fielded four of their January signings, but Oran Kearney's side are in deep trouble.
Alan Trouten (below) gave Championship side Alan Trouten the lead and, after new boy Brad Lyons was sent off, Kevin Cawley extended the lead.
Image source, SNSHT: Kilmarnock 1-0 Forfar Athletic
Kilmarnock aren't getting it all their own way against Forfar, but Stuart Findlay's goal has the Premiership side ahead.
Image source, SNSScottish League Two
Blair Henderson has struck again, the Edinburgh City striker's 29th goal of the season giving his side the edge over Annan Athletic at half-time.
At present, City are poised to stretch their lead, with second-top Peterhead being held at home by Berwick Rangers.
Image source, BBC Sport