It wasn’t quite the club’s record 14-0 defeat, suffered twice against Spalding and British Railways back in the mid-1960s.
But the scoreline will be enough to live long and painfully in the memory of Pilgrims fans, even those who stood behind the goal at Mill Farm, braving the near-freezing conditions and a hailstorm to defiantly cheered their team until the end.
The Pilgrims picked the wrong day for their defence to put in a particularly sloppy, sub-par performance as the National League North’s stand-out side were given the space and time to run riot... comfortably.
But no matter how awful on the eye the Boston backline were - and it was very much a watch-through-your-fingers-if-you-dare type of afternoon - credit must also go to the Coasters’ attacking force, by far the most outstanding arsenal of forward players United have faced this season.
Boston were bad, but Fylde were ruthless, relentless and totally unaware of the old missive about taking your foot off the gas if the game is won by half time.
Amazingly, Jay Rollins - who netted both of Boston’s goals - had put the away side in front in the 10th minute, and a glut of chances then went begging for the team in amber.
But as soon as the Coasters - a fitting nickname after today’s performance - pulled level five minutes later it was obvious who was finishing the day with the points, especially as they led 6-1 by the interval.
United arrived at Mill Farm unbeaten in five away games and hoping to be the first team to beat Fylde in their plush new surroundings, but left well and truly the second best side on the day having lost their last four matches against Fylde, conceding 20 times along the way.
As the game kicked off it was top against 14th, with the Coasters showing exactly why they are unbeaten at their shiny, new stadium.
Sam Finley fired inches wide from 20 yards out and Andy Bond somehow contrived to miss the ball and land comically flat on his face when he just had Dion-Curtis Henry to beat.
But that early pressure didn’t pay off and Rollins gave the Pilgrims a shock 10th-minute lead, finding space on the edge of the Fylde penalty area and drilling coolly beyond Rhys Taylor for his seventh goal of the season.
Full of confidence, Boston took the game to Fylde and would have extended their lead were it not for Taylor pulling off two vital reaction saves to deny headers from Gregg Smith and James Goode, the 17-year-old making his debut on work experience from Peterborough United.
Lewis Hilliard also saw a low effort deflected wide, with Rollins unable to stretch far enough to get a telling touch.
But Fylde were back on level terms in the 15th minute, a swift break finished off by Brendon Daniels, unmarked in the penalty area, taking a casual touch and slotting beyond the wrong-footed Henry.
Bond made amends for that earlier miss when he handed the hosts a 24th-minute lead with a routine finish as Fylde’s swift passing again bamboozled the Boston backline.
Danny Rowe, who had previously tested Henry with a free kick and audacious 35-yard effort off the slippery surface, sodden following a brief hailstorm, made it 3-1 in the 31st minute.
Bohan Dixon set Josh Langley free and, although his effort was screwed wide of the goal, Rowe was lurking at the back post where he was gifted a simple tap-in.
And it was 4-1 seven minutes later.
James Hardy, who had seen a flicked effort hacked off the line by Marcus Marshall seconds earlier, made the most of Henry spilling the ball, spinning away and firing a powerful strike home from a tight angle.
Rowe completed his first-half hat-trick with two late finishes.
Number two came courtesy of more sloppy defending where he and Daniels played pinball in the box before the league’s top scorer smashed home from close range.
And his fifth treble of the season was completed in stoppage time, a close range header with more nonexistent marking.
There was no sign of Fylde taking it easy after the break, Marshall clearing Dixon’s effort off the line within 90 seconds.
But it was the Pilgrims who were on the scoresheet next, Rollins grabbing his second of the day after powering into the box and slotting another powerful finish beyond Taylor.
But nine minutes into the second half Rowe scored his fourth, a clever side-footed finish from distance following good work from Hardy.
That was his final strike of the afternoon as he and Hardy were replaced by Matt Hughes and Matt Blinkhorn, while Boston has earlier handed out a second debut of the day as full back Bradley Peace-McDonald - who has been plying his trade with Bodens in Sweden - replaced Goode.
Fylde netted number nine with 12 minutes to go, arguably the worst of the bunch as Langley’s header creeped through the legs of Henry.
Henry had the final say with a firm save to tip Dixon’s goalbound strike wide, but that will be scant consolation for the United keeper.
On the bright side, at least it wasn’t double figures.
FYLDE: Taylor, Wilson, Kennedy, Langley, Williams, Bond, Hardy (Hughes 68), Finley (Baker 78), Rowe (Blinkhorn 68), Dixon, Daniels; Subs (not used): Collins, Thompson.
UNITED: Henry, Goode (Peace-McDonald 55), Gordon, Miles, Brown, Robinson, Rollins, Maguire, Hilliard (Chippendale 74), Smith, Marshall; Subs (not used): Jason St Juste, Vince, Johnson.
Ref: Martyn Rawcliffe.