IT was the day when Gary Hooper added a couple of goals to his tally for the season – now standing at 20 – and, according to manager Neil Lennon, also added "a couple of million pounds" to his market value.
The margin of their 4-1 victory over Hearts could have been doubled and the visitors would have no grounds for complaint. Even though there was only one goal separating the sides going into the last five minutes of the game Hearts were remorselessly crushed.
Celtic, who can increase their advantage by winning their game in hand at home to Dundee United tomorrow, are now nine points and 16 goals ahead of second-placed Inverness Caledonian Thistle and it says much about the mismanagement of Scottish football in general – and of the failure of the SPL in particular – that the main challenge to the champions is coming from a club whose average home attendances barely scrape over the 4,000 mark.
In truth, though, the biggest threat to Celtic are likely to be complacency and ennui.
The success of Lennon's team in the Champions League has raised the profile of the Scottish game and made a minor dent in the coefficient, but, ultimately, only Celtic will benefit from their European adventure.
The income derived from that only serves to widen the gap between Celtic and the rest and, even when Rangers regain their place in the top flight, they will be so far behind their arch rivals in an economic sense that it could take several seasons, at least, for them to catch up.
On Saurday their fans taunted the travelling supporters about the club's impending demise – a very real concern for Hearts, who, like Kilmarnock, will reportedly receive a winding-up order from a disgruntled creditor this week.
That should not be a source of joy to supporters, whose own institution was minutes away from being dissolved before Fergus McCann stepped in to save them in 1994.
Meanwhile, back at the football – and taking into account the many and varied deficiencies of the opposition – this was an impressive display from the hosts and one which bodes well for next month's visit by Juventus.
Adam Matthews did his best Dani Alves impression while rampaging down the right while Victor Wanyama showed flashes of the imperious form which has seen him scouted by Arsenal, Liverpool and Manchester United.
And then there was Hooper. He took his two goals expertly, was denied a hat-trick only by the tightest of offside decisions and linked well with his supporting cast.
Lennon reiterated Celtic's desire to retain his services but one suspects that, if Norwich City doubled the £5m offer which was rejected on Thursday, he will be sold.
Lennon met with Hooper and his representatives prior to the Hearts match with a view to extending and improving the 24-year-old's contract.
Negotiations are ongoing but Matthews claims his team-mate has been unaffected by the attention he attracts.
"He is very down-to-earth and very relaxed," he said. "He's a brilliant lad. He just has to keep it going.
"Obviously, it's good publicity he's getting, but I'm sure he's happy to stay."
Georgios Samaras had added to Hooper's opening goal before Jason Holt, with Hearts' only shot of any note, reduced the deficit courtesy of a wicked deflection off Mikael Lustig.
Hooper then restored the two-goal cushion before substitute Lassad Nouioui added the fourth with a sublime cushioned finish during stoppage time. . (© Daily Telegraph, London)