Goals by Luke Avis and Spencer Tinkler earned the Tigers a 2-0 semi-final success against cup holders Leicester Nirvana at Carter’s Park and they will now meet Deeping Rangers or Daventry Town in the final.
Holbeach should have won by a bigger margin to match the 4-0 home win over Nirvana in September.
Billy Smith missed three opportunities before the deadlock was broken by Avis as his left-wing cross floated inside the far post.
At the start of the second period, James Tricks and Jack Smith wasted golden chances to increase the lead.
Most Popular
-
1
Peterborough United talking points: 'The diminishing value of Ronnie Edwards, a manager more impressed by hard work and performance than reputation and Bali Mumba's behaviour'
-
2
Peterborough United boss Grant McCann angered by 'disrespectful' Bali Mumba after Plymouth Argyle loss
-
3
Peterborough United linked with Ben Garrity as Port Vale boss seeks to play down link
-
4
Peterborough United should make a couple of changes to their starting line-up for the visit of Sheffield Wednesday
-
5
Posh chairman Darragh MacAnthony: 'Put the hard yards in or we'll get beaten'
The lead was finally doubled from a set-piece. Joe Braithwaite’s free-kick was nodded on by Tricks and the ball was knocked in from close range by Tinkler.
Holbeach were beaten on penalties in the 2016 final by Peterborough Sports.