The Pilgrims went ahead through Dany N'Guessan's third goal of the season, but waves of Mansfield pressure after the break resulted in Richie Barker netting an equaliser from the penalty spot.
In the end a draw was a fair outcome, but a point a piece did little to ease either side's fears just above the trapdoor to the Conference.
Clear openings were at a premium in a drab opening spell. Boston exerted a degree of pressure but the visitors managed to hold firm.
In response, Mansfield's brightest moment was a 14th minute rising 10-yard angled shot by Stephen Dawson after a Danny Reet knockdown but the ball swerved well wide of the target.
It took 23 minutes before Boston managed to test Carl Muggleton in the Stags goal, but even a low 20-yarder by Anthony Elding was comfortably held.
But the game sprang to life on 25 minutes when Boston broke the deadlock.
N'Guessan blocked an attempted clearance by Alan Sheehan, strode forward and lobbed the advancing Muggleton from 20 yards with a cool piece of finishing.
Three minutes before the break Mansfield went close to an equaliser when substitute Giles Coke cut in from the left and his fierce 20-yard effort was partially blocked by David Galbraith before falling invitingly for Andy Marriott to gather.
Boston went close to doubling their lead on 50 minutes when Stewart Talbot crossed from the right but Elding's eight-yard header flashed wide.
Four minutes later at the other end a Gareth Jelleyman corner found Dawson on the far side and his low angled drive was beaten away by Marriott.
The visitors continued to hold all the attacking moves and went close again in the 83rd minute when a raking shot from Nathan Arnold was again well held by Marriott.