They had led Bourne in the United Counties League Premier North play-off final with just quarter of an hour to go.
But with the prospect of going up to the Northern Premier League tantalisingly close, the hosts scrambled home a scruffy equaliser to make it 1-1 and send the game to penalties.
The Poachers briefly had the advantage in the shoot-out as Travis Portas saved Bourne's 4th penalty to send the sizeable away contingent in the 1,781 crowd into a frenzy of excitement.
But after Jordan Tate's effort was also saved, the shoot-out returned to being nip and tuck. The Wakes' 9th spot-kick was converted to put them ahead 8-7 and when Pierce Hudson's shot was parried, Bourne could celebrate back-to-back promotions.
It was an agonising way for Boston Town to end what has nevertheless been a magnificent season that has exceeded expectations.
Jordan Nuttell had given them a 44th minute by tucking home a pinpoint cross from Harry Limb - but it wasn't to be for Chris Funnell's men.
Boston Town: Portas, Worthington (Hudson), Smith, Tate, Ford, Wilson, Bayliss (Gibbons), Maddison, Nuttell (Dakin [Adams]), Limb, Burdass; unused sub: Sellars