Teenage striker Charley Sanders was also on target for the first time as the Pilgrims defeated 10-man Colwyn Bay, despite a Rob Hopley leveller during the second half.
Visiting defender John McKenna had been red-carded for Bay towards the end of the first half but despite a fright at 1-1, the Pilgrims deservedly prevailed after creating a host of clear-cut chances.
With Kallum Smith replacing the injured Gary Silk in United’s starting XI, Conor Marshall reverted to his more familiar right-back position.
The match was preceded by a minute’s silence to mark Remembrance Sunday and once proceedings got under way, Mark Jones soon saw a close-range drive deflect behind off Danny Meadowcroft.
Smith’s inviting cross was then volleyed over the bar from 10 yards by Newsham.
The Seagulls threatened for the first time when Dan Haystead clawed Gareth Evans’ effort on to the post, with Tom Ward completing the clearance off the line.
United continued to create and Smith’s cross was glanced wide by Jones.
Moments later, United thought they had taken the lead when Smith got up brilliantly to power home Marshall’s inswinging cross, but referee Anthony Tankard had already blown for a foul in United’s favour.
Thankfully Tankard’s hastiness with the whistle did not affect United for too long and Marshall was the instigator of the Pilgrims’ opening goal on 27 minutes. He won a 50-50 challenge with Michael Lea before cutting further infield to beat two more challenges and supply NEWSHAM who finished well, low to Chris Sanna’s right, from 18 yards.
Bay replied with Haystead parrying Sean Williams’ free-kick before player-boss Jon Newby hooked an effort well wide minutes later.
The game seemed to swing decisively in United’s favour a minute before the break when McKenna was handed his marching orders after being deemed to have elbowed Jones off the ball.
United started the second half well, looking for a second goal which would seemingly kill the tie off. Jones’ glancing header flew a fraction wide following Ben Milnes’ assist while Jason Stokes’ dipping drive was held by Sanna.
Marshall then whipped in a towering cross which was met by the head of Smith — forcing a magnificent save from Sanna.
Bay equalised on 65 minutes with HOPLEY showing some poise to cut inside Ward before firing the ball low past Haystead.
The leveller brought about the possibility of Bay nicking the victory and Meadowcroft’s downward header was gathered by Haystead as the 10 men sensed an unlikely turnaround. Hopley also headed wide from a Williams corner.
United resumed their offensive with Korey Dyer-Stewart seeing his effort blocked on the line by Meadowcroft, before Sanna excelled to keep out Ward’s towering header from a Ross free-kick.
Boston re-established their lead eight minutes from time with NEWSHAM swivelling to hook home a terrific effort following a ball in from the left.
In a frantic finale, Bay had a strong penalty shout waved away when Gareth Jelleyman appeared to chop down Danny Lloyd in the box but referee Tankard remained unsighted.
Newsham then rattled the post as a hat-trick went begging, but the final say was left to SANDERS, who drove the ball home from 12 yards following Newsham’s clever and unselfish assist.
Boston (4-4-2): Dan Haystead; Conor Marshall, Tom Ward, Nathan Stainfield, Gareth Jelleyman; Jason Stokes, Ben Milnes, Ian Ross, Kallum Smith (Korey Dyer-Stewart 63); Mark Jones (Charley Sanders 83), Marc Newsham. Subs (not used): Sam Craven, James Reed, Ricky Drury (gk).
Colwyn Bay (4-4-2): Chris Sanna; Joel Richardson (Matt Berkeley 84), John McKenna, Danny Meadowcroft, Michael Lea; Cameron Darkwah, Jon Breeze, Sean Williams, Gareth Evans (Danny Taylor 46); Rob Hopley, Jon Newby (Danny Lloyd 83). Subs (not used): David Mannix, Stuart Barlow.
Referee: Anthony Tankard