Celtic were looking to bounce back from mid-week defeat as they made the short journey to the Neuven Stadium.
Celtic started the game well, Declan Walker delivered a free-kick which keeper? Ollie Martin couldn't claim, Jonathan Ustabasi had two shots blocked from close range with the keeper off his line. Ustabasi continued to have some success down the left flank, he got in behind Tyrell Warren twice but the defender did well to block the wingers crosses.
On 21 minutes, Celtic should have taken the lead.
Darius Osei did well to play in Scott Bakkor, the winger squared the ball across goal for Craig Hobson but the ball bounced at the last second and Hobson couldn't get a clean connection and he fired over the bar from just yards out.
Celtic were made to pay as the home side took the lead moments later.
Liam Ellis managed to get past Kallum Mantack, as the broke into the penalty are the pair collided into each other and the referee had no doubt, awarding the penalty. Ben Wharton beat Alex Fojticek from the spot, giving the home side the lead on 24 minutes.
The wet pitch didn't help the game with both teams suffering. Celtic did create one more good chance before the break. On 41 minutes, Osei drove into the penalty area, the angle was tight but he managed to squeeze the ball past the keeper however a Radcliffe defender got back in time to put the ball out for a corner.
Wharton's penalty was the difference as Celtic went into the break a goal down.
Celtic started the second half on the front foot but rarely got past a well drilled Radcliffe defence. It took until the 72nd minute for Celtic to have a clear chance. A low cross from the right found substitute Neil Kengni, his first time shot was parried by Martin out for a corner. Osei had the only other chance for Celtic, he was found in space just outside of the penalty area but dragged his shot well wide. Celtic pressed for an equaliser but Radcliffe stood firm with the home side taking all three points.