Holbeach United extended their losing run to five games on Thursday night.
The Tigers - featuring a number of reserve players and teenagers - missed the chance to go ahead midway through the first half when Josh Ford had a penalty saved.
Rothwell Corinthians completed a double at Sergeants Lawn as Andy White put them ahead two minutes before the break and then he converted a 64th-minute spot-kick.
Paul Newcombe scored the consolation after 77 minutes.
Two months ago the match at Rothwell was controversially abandoned due to Nick Jackson’s calf injury after 73 minutes as the Tigers trailed 4-1.
Holbeach are at home to third-placed Newport Pagnell Town on Saturday.