Bottom place Dumbarton cause a First Division upset as they beat Falkirk 4-3.
Dundee United defender Darren Dods is struggling to return from a knee injury before the end of the season.
Dundee United's Darren Dods is expected to miss five weeks of action as he requires knee surgery.
Dundee United have been boosted by the news that Darren Dods' knee injury is not as bad as initially feared.
Dundee United have been rocked by the news that Scott Severin and Darren Dods will require surgery.
Darren Dods' last-gasp goal earned Dundee United a 2-1 win over Celtic after a late show at Tannadice.
Dundee United have secured the long-term futures of Darren Dods, Morgaro Gomis and Prince Buaben.
Dundee United sailed into the fifth round of the Scottish Cup with a 4-0 win over East Stirlingshire.
Darren Dods has rubbished speculation he is keen to quit Dundee United in search of first-team football.
Hibernian stunned Rangers at Ibrox to climb to the top of the Scottish Premier League.