Berwick's recent upsurge in form continued at Plymouth as the visitors led 16-14 after the fifth race.
They stretched that to 20-16 by the start of the seventh but a home 5-1 saw the sides level 21-21.
They were still all-square after a 3-3 in heat eight but then another home maximum saw Plymouth take a lead they would never surrender.
With just two races left of the night the score was a tantalising 42-36. But a home 4-2 saw any chance Bandits had of victory slip from their grasp.
PLYMOUTH: Ricky Wells (guest) 5+1, Mikkel Bech - Rider replacement, Cory Gathercole 14+1, Todd Kurtz 7+1, Mark Lemon 14, Jake Anderson 5+1, Simon Nielsen 5+2
BERWICK: Edward Kennett 12, Kozza Smith 9+2, Robin Aspegren - Rider replacement, Matthew Wethers 6+1, David Bellego 7, Kasper Lykke (guest) 6+1, Paul Starke 0