Dinnington thirds paid heavily for not turning pressure into points, as they lost to a late converted try against Southwell.
The early exchanges were even until an error by the Southwell full-back allowed Jack Sigsworth in under the posts. David Bell converted.
On a rare second half foray into the Dinnington half, Southwell charged down an attempted clearance, collected the ball and levelled the scores.
Dinnington went back in front as Sigsworth scored in the corner, but Southwell scored under the posts to win it.