The basement side were bowled out for just 91 chasing 227 for victory and are now 13 points adrift of the rest as Boston leapfrogged above them into 11th place.
Having won the toss, Alford skipper Steve Kirkham put the home side into bat first, but had to wait until the score had reached 39 before Andrew White made the breakthrough, bowling Sam Holland for 19.
Tom White removed remaining opener Ben Troops (30) with the score on 62 and the hosts continue to build useful stands right down the order.
The skipper came on to dismiss Adeesha Thilanchana (21) and then bowled his opposite number Jonathan Cheer for 37.
But Mahir Yousuff, coming in at number five, gave the hosts the upper hand, making an unbeaten 74 off 63 balls, with seven fours and a six.
He shared an unbroken stand of 56 with Azeem Qadir (16 not out) as Boston posted 226-5 from their 50 overs.
In reply, Alford lost Joshua Hallam early before Lloyd Batchelor and George Gregory steadied the ship only to both then fall with the score on 31.
Jack Wightwick came in and showed resolute resilience with a battling 49, including two maximums, but support at the other end was in short supply.
His next six partners made just two runs between them, with five falling for ducks, as the visitors were bundled out for 91 inside 30 overs.
Next up is a home match with Bourne on Saturday (noon start).
* The Lincolnshire County League programme was badly affected by the weather, with Louth’s Second and Third teams, and Alford’s Second XI seeing no play.
But the latter two sides did claim wins in the Supplementary Cup, both ties decided by the toss of a coin.