Celtic stay on track to deliver dream treble for Deila
Dundee 0 Celtic 2
History was made after 23 minutes of Celtic's victory over Dundee at Dens Park when John Beaton became the first referee to use vanishing spray in a Scottish domestic fixture.
By that stage, though, Dundee had effectively disappeared from the Scottish Cup fifth round tie, their challenge evaporating when Leigh Griffiths met Mikael Lustig's cross with an adept angled header away from Scott Bain and into the far corner of the net.
Dundee manager Paul Hartley acknowledged that his players "had not turned up" and that, even before Stefan Johansen scored Celtic's second just after the break, they were relying on Bain to keep the score within acceptable bounds.
It was the second time within six days that Celtic had inflicted a comprehensive defeat without having to stretch beyond a two goal margin.
Victory over Rangers at Hampden Park put them into the Scottish League Cup final against Dundee United next month - an event that was tipped further in Celtic's favour when they signed the creative United midfield pair of Stuart Armstrong and Gary Mackay-Steven.
The two-year extension of Kris Commons' contract added to the mood of well-being at Parkhead and the Hoops' straightforward progress into the Scottish Cup quarter-finals concluded what Ronny Deila called "the best week of my time at Celtic."
Celtic can again create a gap between themselves and Aberdeen in the Scottish Premiership table if they beat Partick Thistle at Firhill on Wednesday night in one of the champions' two games in hand over the two teams immediately behind them and eight days later they are at home to Inter Milan in the first knockout round of the Europa League.
Theoretically, Celtic could yet win all four competitions in which they remain, although realistically the best likely outcome is a clean sweep of the Scottish honours, the accomplishment of which would be a remarkable phenomenon for Deila in his first season as a top-flight manager after his arrival from Norwegian side Stromsgodset last summer.
"It is important for the gaffer because nobody knew him before he came here and he didn't know the players," Johansen, who was voted man of the match, said.
"You have to get the best from the players and I think we have all done well with him.
"Speaking for myself, I started the season a bit deeper in the midfield, but now I'm playing as a No 10." (© Daily Telegraph, London)