IT was a routine day at the office for Neil Lennon after a ruthless second-half showing enabled Celtic to come within effectively four games of winning the title for the second successive season.

If nearest challengers Inverness Caley drop points in the coming weeks, it could well be that it is arithmetically all over even before then.

It was a game which became an effortlessly comfortable 5-0 win over a Dundee side who crumbled in the second period of this outing after being reduced to 10 men just three minutes after the interval.

Substitute Matt Lockwood hauled back Gary Hooper as the striker bore down on goal at 1-0. He saw red and Celtic scented blood. They converted from the spot and hit three more before the game was over.

But aside from the points, the goals and imminent proximity of a title celebration, there were various other positive factors the Celtic manager would have found some satisfaction in.

James Forrest, playing just behind a front pairing of Hooper and Anthony Stokes, was at his creative best before he was taken off in the latter stages to catch his breath.

The same applied to Dylan McGeouch, who, after suffering a serious jaw fracture in a pre-season game, has found first-team opportunities tough to come by this season.

Handed a rare start, the winger caught the eye not only with an impressive header which put Celtic out of sight in the second period, but with his overall industrious contribution on the flank.

Stokes, too, posted notice of his presence at the club. The Irishman was not among the goals, but instead turned supplier, taking a hand in a couple as Celtic eased their way through the game.

Yet, for all that it ultimately amounted to little more than a training exercise for Celtic, there had been a degree of resistance from Dundee in early exchanges.

The visitors could have caused a stir by opening the scoring in the early minutes, only for the assistant's flag to catch John Baird offside

As the shrill whistle sounded to signal a Celtic free-kick, Fraser Forster looked to the heavens to give thanks for the let-off. The keeper, who has been so impressive for the club this term, was caught short by the free-kick from Gary Harkins, allowing it to squirm under him before he fumbled it into the net. In short, he did not look particularly clever.

At the other end, his opposite number, Rab Douglas, rued his role in the opening goal of the game when Joe Ledley put the Hoops ahead.

Emilio Izaguirre's cross appeared to have neither menace nor pace, yet the former Celtic stopper parried the cross straight to the feet of the Welshman – captain for the day – who had the simple task of knocking it into the net.

At that stage in the game Dundee, though, were not dissuaded. Heading for the First Division, they nevertheless tried to take the fight to Celtic in the first half and, with a bit of luck, would have found a leveller.

Their task, however, became nothing more than an exercise in damage limitation before they had even had time to regain their stride after the half-time break.

Lockwood, on at the interval, broke up a decent passage of Celtic play when he hauled back Hooper just as the Englishman was ready to shoot.

He saw red for his trouble, Forrest duly converted from the spot and the game was effectively over as a contest.

By the time McGeouch headed Celtic's third, the stage was set for a cricket score. And Celtic didn't take their foot off the pedal.

Ledley added his second of the afternoon, collecting from Stokes and drilling his effort high into the net. The midfielder then had a hand in the fifth as Hooper finally got in on the act, latching on to a high ball from Ledley, bringing it down and slotting into the bottom corner.

Aussie youngster Tom Rogic was brought into the fray to allow him to feel his way into the Scottish game, while there was an appearance, too, for Miku.

Celtic look now to Wednesday night when they square up to Motherwell at Fir Park, before looking to atone for their League Cup semi-final defeat to St Mirren when they play the Paisley side in the Scottish Cup quarter-final at the weekend.

The countdown is on now.