SO here is the debate: is scoring five unanswered goals against an experienced Motherwell more impressive than seven against a boyish Hearts?

The final scoreline is not quite as brutal, but Celtic were as fluid and voracious at Fir Park as they had been at Tynecastle, blowing their opponents away and taking their total to 12 goals in six days. Good teams can hit purple patches like this and, boy, Celtic have struck an abundant seam of form.

There were flicks, feints and backheels long before this drubbing was over. In a ground where they had lost on their last two visits, with the snow fluttering down in the second half, they looked like a set of players simply enjoying their supremacy. Kris Commons scored twice and Efe Ambrose, Anthony Stokes and young substitute Bahrudin Atajic once each. Having scored at the very end of the first half they were rampant in the second, pulling Motherwell all over the place.

Fraser Forster could have been replaced by a traffic cone in the Celtic goal, he was so uninvolved. It will be no consolation whatsoever to Motherwell that Celtic's run of goals is about to run into the brick wall of Barcelona at Camp Nou next Wednesday. Long before the end, the home stands had thinned out to a tiny hardcore of masochists. The team beaten by Albion Rovers in the William Hill Scottish Cup merely served up another serving of misery.

Celtic's sumptuous win extended their unbeaten run of 14 games since the start of the league season, and opened up an eight-point lead at the top. The only cloud on their night was the behaviour of a section of their huge travelling support. A number of smoke bombs and flares were set off from behind the away end goal.

Before kick-off, and again after their opening goal, they discharged them in the stand and even threw a couple of smoke bombs on to the pitch. It was depressingly witless. Flares have been in the news all week on both sides of the border, especially after one was thrown from the Rangers end at Falkirk on Saturday. Some in the Celtic crowd could not resist dragging their own support into the controversy. Singing about Stuart McCall being a "sad orange b******" was also pretty brainless, and after the game it was clear a number of seats had been damaged in the away end too.

On the field, though, Celtic were almost faultless. They had their hosts pegged in their own half for long, yawning chunks of this encounter, working the ball back and fore, and side to side. The movement and the passing was neat and crisp, constantly stretching Motherwell and asking questions of their back four. Commons floated between Stokes and Teemu Pukki, with support coming from a midfield four of Emilio Izaguirre, Joe Ledley, Scott Brown and Mikael Lustig.

They were so overloaded with goals on Sunday that they began last night as if they still had one left to shake out of their system. The play was only seconds old when Commons and Pukki fed the ball wide to Lustig and his firm shot was parried away by Gunnar Nielsen. Soon the goalkeeper was being worked again by a Stokes free-kick. Scott Brown had a very strong penalty claim turned down by referee Steven McLean after firing a cross which struck Stevie Hammell's arm. A deep Izaguirre cross from the left found Lustig flying in for a header which flew over the bar.

Motherwell were defending well, intercepting the crucial final passes and holding their nerve at the back, but it was a relief for their supporters when they finally began to hold the ball up themselves after a pretty torrid opening half an hour. It was after this relative breather that they were at last opened up and conceded the opening goal. Pukki smashed the ball across goal to Stokes and when he fired it back across with equal fizz Commons showed a flash of terrific skill to backheel it into the net.

It might have been a night when one goal would have been enough, but it became a rout. Charlie Mulgrew whipped in a corner which Ambrose scored with a header at the back post. His wife had given birth to their second child, a daughter, Angela, earlier in the day and then he had watched his Nigeria being drawn in a World Cup group with Argentina. No wonder he celebrated with a series of backflips. At the fourth, Izaguirre tried to bend a shot in with his left foot and although Nielsen parried the ball it only went as far as Commons who forced it over the line.

Celtic were upset when Pukki was booked for diving when they felt he should have had a penalty. The Finn did not manage a goal but his low cross allowed Stokes a simple finish for 4-0. The young Swedish substitute, Bahrudin Atajic, coolly lobbed the goalkeeper for the fifth. By then Motherwell were a sorry sight.