Martin O'Neill sent Celtic out hoping the untimely revelations over his delay in signing a new contract had not distracted his title-chasing side from the task in hand of moving level on points with Rangers.
O'Neill was without Chris Sutton, John Hartson, Johan Mjallby, Steve Guppy, Robert Douglas and Magnus Hedman and they were joined on the sidelines by Joos Valgaeren, who suffered a back injury in Saturday's 4-1 victory at Dunfermline.
His replacement, skipper Paul Lambert, stayed in the side in the only change from the weekend with Shaun Maloney staying alongside Henrik Larsson in attack. With uncertainty raging over Falkirk's promotion situation, the
Lanarkshire outfit were still fighting for their life and in many cases their futures.
The Old Firm brings out the best in Scotland's brightest young hope James McFadden, and he looked eager to
inspire Motherwell from the first whistle.
He picked out Steven Hammell with a superb crossfield pass in the second minute, but with Celtic stretched his team-mate failed to make the most of the chance.
The visitors responded well and Alan Thompson fired a trademark low drive which took a deflection to take it just past the upright.
But the resulting corner brought the first real chance which fell to 'Larsson.
Thompson swung in the free-kick which Bobo Balde missed, but with Stephen Woods scurrying across his goal the Swede somehow prodded the ball past the post from two yards.
Motherwell did lose a player though in the 19th minute after Cowan was stretchered off after an innocuous challenge by Ulrik Laursen to be replaced by William Kinniburgh.
But on the half-hour the crowd saw the worst of the young McFadden when he appeared to raise his hands to Lennon after the Northern Irishman fired the ball at him.
Amazingly only the Celtic man was cautioned, but moments later Motherwell were reduced to 10 men.
Thompson went down after an off-the-ball incident involving Derek Adams and after consultation with the linesman, McDonald showed him the red card. Celtic went ahead through Petrov in the 35th minute.
The Bulgarian was left in acres of space down the right and Larsson threaded the ball through to him to blast past Woods' despairing dive.
Motherwell were clearly losing their discipline and Corrigan was booked for a reckless lunge on Lambert, who returned to action after receiving treatment.
In injury time at the end of the first half Woods redeemed himself for Celtic's goal when he pushed Petrov's right-foot shot away.
The half-time break failed to settle Motherwell and Vaughan was the next man booked for a foul on McNamara.
But Maloney came within inches of doubling Celtic's advantage just five minutes after the restart. Larsson
unselfishly headed Lambert's cross into his path and he fired wide from the edge of the area.
But the writing was on the wall and Celtic did double their lead in the 56th minute and it was Petrov again who continued his rich vein of scoring form.
Larsson found him on the overlap and he showed all the calmness of the Swede to chip the ball over the
Celtic sensed they could score more goals and they squared the goal-difference at the top of the table in stunning style.
Lambert and Maloney exchanged passes for the Scotland international to fire past Woods from close range.
The midfielder was not finished there and he produced arguably one of the goals of his career in the 65th minute to score Celtic's fourth.
Again he played a one-two with Maloney, but this time he controlled the ball and lobbed the ball over the stranded Woods and into the corner of an empty net.
Motherwell again lost their cool and McFadden and Partridge joined the growing list of cautions McFadden and Clarkson were both hauled off by Butcher, perhaps fearing that a sending off would rule them out for the vital run-in.
Larsson could have rounded the result off in some style with four minutes left, but he fired over from eight yards after substitute Jamie Smith had done well down the right.
Broto enhanced his growing reputation in the final minutes when he saved from Richard Offiong to make sure Celtic were top of the table last night.
MOTHERWELL: Woods, Corrigan, Partridge, Vaughan, Hammell, Cowan, Adams, Leitch, Pearson, McFadden, Clarkson.
CELTIC: Broto, McNamara, Balde, Laursen, Agathe, Lennon, Lambert, Petrov, Thompson, Maloney, Larsson.
Referee: D McDonald (Scotland).