A potentially definitive week in Scottish football which began on the day designated as the Ides of March ended with the lethal blow being struck by one so familiar that Dundee United's leadership could have been forgiven for coming over all Shakespearean.

 

Et tu Gary?

Their former ally had looked a tad sheepish as the pre-match handshakes were completed and he headed off to join the rest of the Celtic squad, while he initially waved away the celebrations after delivering a rapier thrust that was clinical enough to make any assassin proud.

The visitors having offered little by that stage all in attendance knew there would be no meaningful response. Two more goals before the break, Mackay-Steven also helping tee the second up for John Guidetti before, in among a group of bodies, Jason Denayer casually back-heeled the next past Rado Cierzniak, bordered on unnecessary cruelty.

"It's obviously demoralising coming and getting beaten in the past three games when there was so much belief that we could go and do it," admitted Blair Spittal, one of a group teenagers in whom Jackie McNamara, United's manager, has to invest hope after admitting his men looked like they felt sorry for themselves during that first half and must now use the international window to regroup.

By contrast, the depth of resource Celtic now boasts was demonstrated by Mackay-Steven and Stuart Armstrong, his fellow recruit from United, being part of a completely changed attacking force to that which overwhelmed United three days previously in the Scottish Cup replay.

So much so that after a week that has seen them lift the season's first piece of silverware, take a vital step towards extending their record number of Scottish Cup wins and pretty much secure the Premiership title no-one ever really doubted they would retain, it is debatable whether the break comes at a good time for Celtic given the level of confidence that was described by a player who is often considered something of a weak link.

"Right now it will take a lot of effort for another team to stop us because we are playing at our best," Efe Ambrose said afterwards.

"For the rest of the teams it is going to be difficult for them to withstand what we have right now. The calibre of player and the squad we have is huge and everyone is up to his best now and in his best form and shape which makes it difficult for the manager to pick his starting eleven so it's been great."

Throw in Aberdeen's failure to take full points from their visit to Dens Park immediately before this match kicked off and the week commencing March 15 could hardly have gone better for men eyeing their place in history with ever greater avarice.

"It's been a great week but we don't want to be content with what we have done, we want to look forward to the next game which is more important," said Ambrose.

"We want to get all the wins we can so we can defend our title and get to the final in the cup and see if it is possible to win the treble which is our main aim."

Only the danger that, as Celtic supporters well, is inherent in cup football, now looks to stand between them and that target since, if the cruise to the Premiership title has not been quite as smooth as anticipated in a season that has seen four other teams top the table, a five point advantage with a game in hand plus the insurance of goal difference that is 22 better off than Aberdeen's still looks unassailable, but the impression is that Celtic will principally be driven on by internal factors.

"Anything can happen in football, so we don't put that in our head," Ambrose continued when asked if he had begun to fantasise about the moment the treble was complete.

"Everyone wants to beat Celtic which makes it more difficult for us and the more you need to prepare and work to the tactics the gaffer wants us to play. We just have to keep the team together, one spirit, one heart."

As for the vanquished United, this ultimately had less the feel of the grandeur of Shakespearean tragedy and more that of a cheesy Hollywood franchise gone one step too far.

Beginning in credible fashion with the plucky underdog taking on the champion, battling to a standstill and, cut to shreds, drawing on every ounce of courage to hang on for a draw, they had, come this fourth instalment, run out of ideas, the belated reintroduction of characters who had previously served this tale well generating an all-too-predictable outcome.

It may not be completely over for them, though, as, to quote the eminently more understandable Stallone, United now seek to discover how much they can take and keep moving forward.