Mansfield's nine-game unbeaten run in all competitions was ended by a 2-1 home defeat against Peterborough, with the visitors punishing the Stags after weathering a one-sided opening period.
Mansfield dominated the first 45 minutes but were undone by second-half goals from Jimmy-Jay Morgan and Harry Leonard, leaving George Abbott's debut goal to count for little.
Stags Frustrated By Bass
Mansfield controlled the early exchanges as Regan Hendry fired inches over and Luke Bolton was denied twice by Alex Bass, who also saved well from Frazer Blake-Tracy.