IF it wasn’t for the empty stadium and the trifling matter of the 20-point gap that exists to Rangers at the top of the table, you could have been forgiven for thinking it was the good old days for Celtic at Rugby Park.

Certainly, the champions looked a lot more like the side we have come to know over these past few years on a night of welcome returns for Neil Lennon’s men. The welcome return of something approaching their best form, the welcome return of some zip and desire in their play, and the return of Scott Brown to the starting XI which proved so pivotal to those outcomes.

The captain nodded home the opener for his side just after the half hour, but it was his drive and constant haranguing of teammates that was the vital contribution to a team display that was light years ahead of the dismal weekend showing against St Mirren.

It may all be too little, too late, of course, and manager Lennon will be wondering just where this team has been hiding for the past few months. But with positives so thin on the ground for his side recently, he will have enjoyed plenty of them here.

There was the return to form of Odsonne Edouard, who scored a second-half double. Two assists for the consistently impressive David Turnbull. A solid debut showing for deadline day signing Jonjoe Kenny. There was even an impressive goal from Albian Ajeti to round things off.

All in all, it was the type of victory that may once have been considered routine for Celtic, but will no doubt be keenly savoured by their under-fire manager.

As for Killie, well, they too will hope for better days ahead. With manager Alex Dyer falling on his sword following St Johnstone’s comeback win here at the weekend, they were always going to be up against it as caretaker manager James Fowler temporarily took the reins.

The headline news for the hosts was that captain Gary Dicker was back in the line-up to partner Alan Power in the midfield, with deadline day signings Zech Medley and Brandon Pierrick having to make do with a place on the bench.

Celtic manager Lennon shook things up after the dismal defeat to St Mirren, with Kenny in at right-back, Stephen Welsh replacing the hapless Shane Duffy, Brown restored to the line-up in place of Ismaila Soro, Ryan Christie brought in on the right of the attack for Moi Elyounoussi and Ajeti given a start ahead of Leigh Griffiths up top.

Celtic immediately looked much sharper than of late, and swarmed around the Kilmarnock goal in the opening 10 minutes. Edouard had a half-hearted penalty appeal waved away before fluffing his lines after a fine passing move saw him free in the box, but overall it was much better from the visitors.

That is until the ball went anywhere near their own area, with a high inswinging cross from the Killie left by Rory McKenzie causing all sorts of consternation. With Scott Bain nailed to his line and Kristoffer Ajer ball-watching, Chris Burke stole between the pair of them and really should have put the hosts ahead, but the veteran winger fluffed his finish to let Celtic off the hook.

Turnbull bent one just wide at the other end as Celtic responded, and just before the half hour, he teed up his captain for the opener. Ajeti won a corner down the right and Turnbull swung in a delightful cross that Brown met with a clever header to guide into the right-hand corner of Colin Doyle’s goal.

The second half started as the first had ended with Celtic in the ascendancy, and the incisive passing of Turnbull was causing all sorts of problems. Twice he picked out Edouard in great positions in quick succession, the striker taking too many touches when in on goal the first time around, and then being wiped out by Dicker the second time around in the minds of everyone except referee Kevin Clancy.

The official was at the centre of controversy moments later as he awarded Celtic a penalty when Ajeti went down as Doyle dived at his feet. Clancy took the advice of the far-side assistant and then took an age to point to the spot, and the Killie players were incensed when he belatedly did so, feeling the Swiss striker had gone to ground rather easily.

Certainly it looked that way, but regardless, Edouard was tasked with slotting home from 12 yards and he squeezed the ball low past Doyle to his left to double Celtic’s lead.

Killie should have had one back immediately as Burke headed off the post from point-blank range, and the game was over as a contest soon after.

Again, it was the combination between Turnbull and Edouard that caused all the problems, the midfielder getting his head up and curling a peach of a ball high over the Killie defence and perfectly into his teammate’s path to finish coolly past Doyle for his second.

It was then a case of whether or not Celtic fancied another, and that they did. Ajeti did well to take down a long ball and showed great strength to hold off the challenge of Clevid Dikamona before finishing across Doyle.

Is this the return of Celtic? Only time will tell, and time is well and truly against them.