Celtic eased to within four games of back-to-back titles – and pushed Dundee closer to the precipice – with an economical win at Parkhead, where Joe Ledley's first-half opener was supplemented after the break by a James Forrest penalty, a Dylan McGeouch header, another Ledley strike and Gary Hooper's 15th league goal of the campaign.
Neil Lennon's players now have a points lead equivalent to seven victories, with 10 matches remaining – although second-placed Caley Thistle have a game in hand – and they have a goal difference so substantial that it is effectively worth an extra point.
It was as a former Rangers player that Dundee interim manager John Brown was greeted by the Celtic partisans who hail the team buses as they arrive. He acknowledged the derision with a benign smile, having had plenty of practice during his career at Ibrox.
Brown's long experience also guaranteed he would expect a Hoops side closing in on the title to pummel his players but after only six minutes Dundee had the ball in Fraser Forster's net from Gary Harkins' free-kick.
The goalkeeper allowed it to squirm through his grasp and across the line but his embarrassment was relieved by the far-side assistant, who spotted Ian Davidson straying fractionally offside.
Forster's opposite number Rab Douglas was granted no such reprieve when he spilled a cross from Emilio Izaguirre, and Ledley clipped it precisely beyond him.
Having allowed Celtic to go ahead so cheaply, Dundee were almost handed a reciprocal gesture by Efe Ambrose, who allowed Brian Easton to rob him close to goal – in about the same position where his misjudgment of a punt let Juventus in for the first of their three Champions League goals – but this time the Nigerian recovered to thwart the defender.
Harkins' frustration was extended first when Forster tipped a rising effort over at full stretch and again, moments later, when he met the corner with a powerful header off the bar.
Any doubt about the outcome evaporated immediately after the break, in dire circumstances for Matt Lockwood. The left-back replaced Easton at half-time but within three minutes he had returned to the dressing-room, having been shown a red card for fouling Hooper to concede a penalty, which was dispatched efficiently by Forrest.
There was no way back for Dundee and what followed was an exercise in inevitability, emphasised by the ease with which McGeouch, Ledley were able to add to their misery with unopposed efforts, all of which found the net. (© Daily Telegraph, London)