Mossley's under 21 team avenged the first team defeat by neighbours Stalybridge Celtic earlier in the week thanks to a clinical first half performance.
Celtic had the first attack but it was Mossley who took the early lead. Debutant Kyle Clarke finishing well after his first effort was blocked.
There were chances at both ends before Celtic equalised on 17 minutes when a Stalybridge forward was given too much time and space to get his shot away.
Within three minutes Mossley had opened a two goal lead. Firstly Akim Samms restored Mossley's lead with a clever finish and a minute later later Kyle Clarke headed home Samms' lefft wing cross.
Akim Samms scored his second of the night on 30 minutes latching onto Clarke's clever pass and six minutes later Kyle Clarke completed his hat-trick when he pounced on a goalkeeper error.
Celtic reduced the arears just before the break when a Celtic player raced through from a ridiculously off-side position to chip the ball over the advancing Cawthorne.
The pace was less frantic after the break and there were far less chances for either side. Celtic reduced the arrears again from the penalty spot on 55 minutes.
The scoring was completed ten minutes from time when Papis Touray clipped the ball over the stranded keeper after he latched onto a poor clearance.