United led 2-0, courtesy of Will Langford's well-taken second minute effort and Josh Doran's wonder strike eight minutes after the break.
The visitors cut the deficit from the penalty spot in the 90th minute through Matty Telfer and then grabbed a point deep into added time through George McArthur.
Boston: Cameron Fox, Rueben Fogg, Josh Doran, Will Langford, Ellis Perry-Burdett, Finley Ging, Hugo Hunt (Rhys Smaller 76), Kris Zaluzinskis, JJ Ward (Charlie Brooks 85), Joe Wilkinson (Jake Henderson 64), Luke Horne (Brenden Parker 74). Sub (not used): Tyler Griffin (gk).
Referee: Trevor Basker.