Vince's early double and Bailey Forth's strike before half-time handed the Pilgrims a 3-1 interval lead.
CV Reds, however, came roaring back after half-time to snatch a share of the spoils and leave Boston two points behind Division H leaders Basford United.
Boston (4-3-3): Harry Payne; James Gordon, Jack Withers, Bailey Forth, Callum Rodger; Jordan Tate, Harry Vince, George Hobbins; Ben Lawrence (George Smith 46), Liam Adams, Jack Brown (Connor Stocks 60). Subs (not used): Jenson Ball, Peter Evison, Arkadiusz Michalczyk.