Tom Stewart was beaten for the first time in pre-season, but there was nothing he could do about it. The same was true of the equaliser, with the winner a silly conceded penalty.
Both defences were compact and difficult to break down early on, Chris Holroyd coming closest for Celtic with a header off a lifted ball from Keano Deacon, but he cleared the bar. A congested box saw the opener for Mossley, as Jordan Butterworth fired back in a corner through a crowd, his shot initially going for the bottom left corner, and Tom Stewart well on his way to covering it, but a double deflection saw the ball diverted into the opposite corner, with nothing the Celtic custodian could do.
The Lilywhites kept their compact formation at the back, with Celtic trying to play through them and the game became a combative battle Harry Freedman found some space with a one-two off Holroyd, but Liam Lovell was well placed to catch comfortably. Bradley Knox leapt highest on a corner, but couldn't bring the ball back enough, the ball bulging the side netting from the wrong side. Anthony Williams tried a twenty-yard effort, firing through a crowd, but there was no deflection this time, Lovell catching easily.
It took until the final minute of the half. Butterworth upending Keano Deacon as the new signing was about to burst into the box. Harry Freedman took the free kick, with a little Johnny Wilkinson-esque shimmy before stepping up and curling the ball up and around the ball and back, Lovell statuesque as it flew into the top corner.
Krisel Prifti was one of the numerous subs at half time and proved instrumental in the half, forcing a decent stop from Lovell and putting a free kick only narrowly wide. And it was Prifti's twisting and turning in the box that saw a Mossley trialist grab his shoulder and pull him back. A certain penalty and Kyle Hawley stepped up to take it, sending Lovell the wrong way with a decent strike to put Celtic in front.
Mossley should have equalised in the dying moments when an uncleared corner pinged in the box and fell for Ryan Shenton, but amid unheeded claims for handball, Shenton sliced his shot horribly wide from close range with the goal at his mercy.
There were lessons to be learned for Celtic today, with a lack of width against a tight defence, but there was commitment and drive, and of course, a sublime free kick from Freedman.