The three points reduced the gap at the top to 10 points again, following Rangers' 6-1 win over Dundee on Saturday but, although Celtic are playing well and scoring goals, they are running out of games.
The first clear chance of the night fell to Motherwell, a mistake by Johan Mjallby giving Lee McCulloch a clear sight of goal, but his shot at Jonathan Gould was too straight.
Three minutes later Motherwell were reduced to 10 men as the game boiled over. John Spencer tangled with Jackie McNamara and raised his arm to the Celtic man, leaving the referee with no option but to send him off.
Seven minutes later Celtic took the lead, from the spot. Stephane Mahe collected a return ball from Paul Lambert but was followed by Michel Doesburg. Henrik Larsson fired the penalty home.
At that stage Motherwell might have struggled, but they rallied with an equaliser five minutes later from the foot of Ged Brannan, whose 20- yard free-kick thundered into the bottom corner.
Celtic were ahead just four minutes later, again from a free-kick. This time Lubomir Moravcik sent his shot curling ing past Steve Woods.
After half-time Celtic moved 3-1 ahead, thanks again to Larsson. With three defenders clustered around him there appeared no way out, but he managed to find space before driving a low shot past Woods.
Celtic lost Moravcik after 70 minutes with hamstring trouble. His exit paved the way for a return to action in midfield, after serious injury, for Craig Burley, who celebrated by scoring four minutes later.
In the final six minutes Celtic produced a further three goals, the first from Mark Burchill, another substitute. Larsson then made it six and, with two minutes remaining, the Swede polished off the night with a fine header for his fourth.
Motherwell (3-4-1-2): Woods; Craigan (Nevin, 30), McGowan, Teale; Doesburg, Brannan, Valakari, May (Ross, 69); Spencer; McCulloch, Coyle (Adams, 63). Substitutes not used: Ramsay, Bannister.
Celtic (3-4-1-2): Gould; Boyd, Riseth, Mjallby; McNamara, Lambert, Blinker, Mahe (McKinlay, 78); Moravcik (Burley, 70); Larsson, Brattbakk (Burchill, 82). Substitutes not used: Kerr (gk), Healey.
Referee: K Clark (Paisley).Reuse content