Giorgos Giakoumakis scored a second-half double as Celtic booked their place in the Scottish Cup semi-finals with a straightforward 3-0 win over Dundee United at Tannadice.
The visitors, who made it 30 domestic matches in a row unbeaten, were comfortable for most of the evening following Callum McGregor 's early opener, although they were aided significantly by a terrible blunder from United goalkeeper Benjamin Siegrist for their second goal.
The result means the last four of Scotland's oldest knockout tournament is made up of the two big clubs from Glasgow and Edinburgh for the first time in its history.
