Goals by Scott McDonald, Jan Vennegoor of Hesselink and Georgios Samaras proved enough to secure the points but it was Gretna that emerged from the game with more credit.
But their hopes of a bumper pay day given their financial crisis did not transpire with less than 4,000 watching the game.
Gretna's makeshift side stifled Celtic for long periods of the first half and they even threatened themselves on the odd occasion.
Shunsuke Nakamura saw a shot blocked by Danny Hall after 19 minutes as Celtic finally took a grip on the game. Aiden McGeady then forced a fingertip save from Greg Fleming as the goalkeeper manager to claw the ball over his crossbar.
Nakamura tried his luck with a free-kick which beat the defensive wall but flew straight into Fleming's arms.
Gretna had a rare chance after half-an-hour when good work by Ben Wilkinson created an opportunity for Brendan McGill but he could not pull the trigger and Stephen McManus scrambled the ball clear.
Celtic's frustration was obvious when Scott Brown was booked for a wild challenge on Ryan Baldacchino before half-time.
Barry Robson forced another fine save from Fleming before Brown headed wide as Celtic tried to take the lead before the break.
Just when it looked as if Gretna would hold out, McDonald struck with a simple goal three minutes before the interval.
A long clearance from Artur Boruc was headed on by Vennegoor of Hesselink and McDonald side-footed the ball past Fleming.
Vennegoor of Hesselink should have added a second before half-time but failed to find a finish with Gretna caught short at the back.
But Gretna stuck to their task and McGill fired a shot narrowly wide early in the second half to show they were still in the game.
Nicky Deverdics had a better chance in the 59th minute from McGill's pass but he could not get any power in his shot and Andreas Hinkel managed to scramble the ball away for a corner.
Celtic responded and Fleming made another fine save from McDonald but it was the last piece of action for the striker who was replaced moments later.
Celtic added a second goal in the 70th minute when Vennegoor of Hesselink headed a great cross from McGeady home, and Samaras scored the third with two minutes left, an excellent finish into the roof of the net from another McGeady cross.