The Pilgrims were 4-0 down after 37 minutes thanks to Daniel Maguire's hat-trick and one from Nathan Buddle.
Harry Vince did get one back for Boston on the stroke of half-time and then Karl Hawley added another in the second half, but Jarratt Rivers dismissed any lingering doubt about the final result with a fifth for the home side late on.
Understandably, manager Adam Murray was far from pleased with the defeat and now he has to pick his side up for another away trip to Bradford.
"As you can imagine, the mood in the dressing room is very sombre," he said. "I think it is when you put in a performance like that, especially in the first-half. The second half was a lot better, it was more like us, but you're chasing it and there's gaps everywhere and you concede again.
"We can't put in bits of the game like the first-half, it's just not acceptable at any level, be it this level, local Sunday league, the Premier League, you can't go about your business like that.
"At times in that first-half of the game I couldn't believe what I was seeing. It's not the stuff we drilled in or what we work on. Individuals have to take responsibility for that.
"We work way too hard to be let down by people thinking they can coast through certain moments of the game. We go again on Monday. There isn't a better time to put it right and to get ourselves up and running again."