Stilian Petrov kept Celtic at the top of the Scottish Premier League with a late strike against Hibs at Easter Road.
A stuttering performance from the champions looked likely to hand Hibs a point but the Bulgarian international struck 14 minutes from time to assure Celtic of all three points.
The goal came just moments after Hibs had made a double substitution in midfield and it proved a costly switch with no-one picking up Petrov's run.
Celtic were without Henrik Larsson (illness) and Chris Sutton (hip injury) and both face a fight to be ready for Saturday's crunch encounter with Rangers.
Hibs were also without their main goal threat with Mixu Paatelainen also missing out through injury. Chances were few and far between in an evenly-balanced first half in which Hibs created the best goalscoring chance.
Midway through the half, Derek Townsley beat Robert Douglas with a header from a John O'Neil corner but Alan Thompson cleared off the line.
Celtic's first-half efforts were restricted to long range with Thompson whipping a 27th-minute shot a yard wide and, four minutes later, just a yard too high with a 22-yard free-kick.
Ian Murray had a chance for Hibs two minutes from half-time but his effort was tame and Douglas saved easily. Hibs had a decent break at the start of the second half when Tom McManus raced clear but his final cross was too high for Townsley.
Celtic hit back and Thompson fired a long-range shot high and wide before Celtic had a great chance to take the lead in the 66th minute. David Fernandez laid the ball on a plate for John Hartson but he wanted too long and sliced his final shot well wide.
Hartson squandered another chance four minutes later when he was put clear but his lob was far too high and Nick Colgan was not troubled.
Just when it looked as if Hibs would claim a point, Hartson released Petrov and the midfielder pick his spot to slot a 15-yard shot past Colgan.
McManus missed a chance to equalise in the final minute when he headed over from close range