Rangers and Dundee United booked their places in the semi-finals of this season's William Hill Scottish Cup on a dramatic day of cup action.

Rangers defeated Scottish Premiership side Dundee 4-0 at Ibrox thanks to goals from Harry Forrester, Jason Holt, Andy Halliday and Lee Wallace. The result means Rangers will be in their second William Hill Scottish Cup semi-final in three seasons.

Their opponents in that last semi-final, Dundee United, also reached the final four on a dramatic day in Dingwall against Ross County. Liam Boyce had given the Staggies the lead before Henri Anier equalised for the visitors in the second half. United's Mark Durnan was sent-off moments later for a foul on Brian Graham, who then restored the lead for County with the resulting penalty. However, another goal from Anier and a late header from Billy McKay maintained Dundee United's status in the competition.

On Sunday, Celtic eased past Greenock Morton at Celtic Park with goals from Leigh Griffiths, Gary Mackay-Steven and Callum McGregor. Hibernian and Inverness Caledonian Thistle drew 1-1 at Easter Road, and will replay next Wednesday.