An RAF helicopter had delivered the match ball to the officials before the game and with a little hindsight Boston's players would surely have left with it.
The Pilgrims' poor marking was exposed after just 88 seconds when Paul Arnison launched a hopeful cross to the back post.
Derek Holmes rose unchallenged and nodded down to the free Lumsdon who volleyed in easily from 6 yards past Michael Kuipers.
Further chances came and went for the Cumbrians with Holmes heading straight at Kuipers when it seemed easier to score.
Asa Hall went close for the Pilgrims on three occasions but keeper Keiren Westwood was never really troubled.
The home side doubled their lead after 20 minutes thanks to an instinctive Karl Hawley touch.
Lumsden's corner drifted into the six yard box and with the ball already past him Hawley flicked out a leg to backheel in from close range.
But Boston fought back in the second half and halved the deficit thanks to a Chris Billy own goal.
Jamie Clarke's wild shot looked to be headed for a throw in before Billy inadvertently deflected the ball past the wrong footed Westwood.
With Carlisle now on the back foot the Pilgrims could smell an equaliser until the introduction of man of the match Hackney.
The speedy 22 year old caused no end of problems for the tired Boston defenders and latched onto a Hawley pass to outrun his marker and fire in spectacularly from the edge of the box.
But with 7 minutes to go Boston's Simon Rusk put the visitors back in with a shout, but their late pressure was to be in vain.
Keeper Kuipers had gone forward for his side's last attack but was caught out and Hackney ran from his own half to calmly chip the ball into the unguarded goal from 25 yards.