Another sending off, this time Mathew McNeil, marred this otherwise solid Celtic performance.
But at least the Curse of Celtic's Cup Campaign held off, and it was relatively dry.
Chorley must have realised what they were up against when on five minutes, Sullivan latched onto a Green through ball to slot to the right of the off-form Chorley keeper.
Sullivan returned the favour, although some might have thought Sully was attempting to score himself when the ball zipped into the six yard box. Green got a foot to it, this time, it went past the keeper's left arm.
Then McNeil got upset when the referee gave a foul to Chorley, when he felt it should have been to Celtic. The referee showed him the yellow card for dissent - he argued about that, and got sent off.
Celtic can beat better opponents than Chorley with a man down, and McNeil's early bath did not faze them too much. Evans came close a few minutes later, when, after rounding a defender, he was put under presure by the keeper and the ball trundled through the thick mud, allowing Flemming to come back and clear off the line. And seconds later, a Ward free kick, saw Parr's header scrape the left hand post.
Chorley had a good spell mid way through the half, forcing Locke and Williamson to both make excellent tackles at the edge of the Celtic box. But Locke, Williamson and Ogley were all stalwart in defence, forcing Chorley to have long range efforts.
Chorley did score though, when Evans got his head to a whipped in ball. He was well offside before he got there though, and Celtic remained two to the good. Chorley can also count themselves unlucky when a richocheting ball in the penalty box went out for a goal kick just minutes later.
Celtic just about deserved their lead at the half time whistle.
Wilson did his magic in the dresing room, and the side came otu looking like they had not lost a man.
However, there were gaps, and Chorley had two good attempts with both Hicks and Evans shooting wide.
The Celtic Evans then showed them how to score, by breaking from midfield, and rounding the flailing keeper to slot home, though the ball must have been travelling at one mile an hour when it crossed the line.
Chorley came rigth back from the kick off, with Evans forcing a good save from Fish with a powerful twenty yard drive.
Again, though Chorley showed their inexperience, when two defenders went for the same ball after Fish's kick, allowing Evans to nip in and steal the ball. Obviously a sporting chap, Evans dallied with his dribbling to allow them to catch up, so that he could round them both, leap the keeper and put in a more convincing goal.
Crookes came on for Locke, and this seemed to unsettle Celtic, leaving a large hole in the defence, which allowed first Hicks to get through, and score, and then Evans to get through and score. Although Sully did have a fantastic shot saved by the keeper, proving he wasn't just a pretty face.
The two goals geed up Chorley, and they won several corners in the last twenty minutes, pressing Celtic back. Ogley and Williamson remained solid, and with the addition of Pickford to free Crookes into his more usual defensive role, Celtic blocked the holes, and Chorley could no longer break through.
Celtic finished on top, and looked all game like they would do.