It was an exciting Saturday of William Hill Scottish Cup action with nine teams progressing to the fifth round.
The biggest result of the day was at Bayview Park as Brora Rangers knocked East Fife out of the cup. The Cattachs continue their great run in this season's competition having already beaten league opposition in the third round. They are still to concede a goal in the Scottish Cup this season.
Inverness Caledonian Thistle scored late to secure a replay against Dundee. George Oakley's 87th minute equaliser means they will go again on Tuesday, 30 January in Inverness.
Motherwell are into the fifth round draw following their win over local rivals Hamilton Academical at Fir Park. Kilmarnock left it late to beat Ross County. Lee Erwin with the winner from the penalty spot in the 88th minute.
Gary Mackay-Steven scored a fantastic goal against St Mirren in Saturday's early kick-off. He scored Aberdeen's fourth in a 4-1 win.
Elsehwere there were wins for Celtic, Partick Thistle, Greenock Morton, Dundee United and Ayr United.
William Hill Scottish Cup Fourth Round results
Aberdeen 4 - 1 St Mirren
Albion Rovers P - P St Johnstone
Match to be played on Tuesday, 23 January
Alloa Athletic 0 - 2 Dundee United
Ayr United 4 - 1 Arbroath
Celtic 5 - 0 Brechin City
Dundee 2 - 2 Inverness Caledonian Thistle
Replay to be played on Tuesday, 30 January
Dunfermline Athletic 1 - 2 Greenock Morton
East Fife 0 - 1 Brora Rangers
Formartine United P - P Cove Rangers
Match to be played on Wednesday, 31 January
Kilmarnock 1 - 0 Ross County
Livingston P - P Falkirk
Match to be played on Tuesday, 23 January
Motherwell 2 - 0 Hamilton Academical
Peterhead P - P Dumbarton
Match to be played on Tuesday, 30 January
Queen of the South 1 - 2 Partick Thistle
Fifth Round Draw
The William Hill Scottish Cup Fifth Round will take place on Sunday at Tynecastle Park following Heart of Midlothian v Hibernian.