In conditions which suited them, Otley were a touch disappointed to go into the break just 10 points ahead, more so when heavy rain fell throughout the second-half to the delight of Cinderford who drew level within 10 minutes of the restart.
It was a fiery contest throughout with defences on top but Otley took the lead with a 20-metre penalty from fly-half Jervis Manupenu.
After promising much, Otley went further ahead, Cinderford winger Matthew Betty receiving a yellow card when illegally helping to stop centre Joe Barker's mazy run.
The penalty on halfway was sent into the corner by Manupenu, who went on to convert after replacement Jamie Sutton had been driven over.
Otley were rocked back on their heels by Cinderford's aggressive start after the break and, after conceding a 10-metre lineout, they just managed to hold the drive but a neat chip from fly-half Mark Davies fell right for centre Kyle Palm, Davies converting and, four minutes later, dropping a goal to level the score.
With second-row pair Joe Quinn and Dominic Barrow excelling in the lineout, Otley began to reassert themselves and they retook the lead with a penalty from Manupenu, who set up the final try with a fine chip for winger James Twomey to run onto.