Two games remain of the Moore and Smalley Palace Shield Premier Division with Garstang still nine points clear at the top.
Mark Walling’s players stayed in pole position thanks to their 68-run defeat of bottom side Rufford on Saturday.
Garstang batted first and racked up 233-4 from their 45 overs, led by the skipper.
He was out in the last over after making 91, while Michael Walling also contributed 66 to their formidable total.
It was always likely to prove a touch target for the strugglers and so it proved with Rufford all out for 165, giving Garstang victory and the full 12 points in the process.
However, the news was not so good for the second and third XIs as both of them were beaten.
The seconds went down by nine wickets when they met South Shore at the Riverside.
Garstang batted first and were skittled for 82 in the 32nd over.
Opener Chris Redman was their top scorer with 24 but Alasdair Egerton (17) and Tom Winstanley (14 not out) were the only other batsmen into double figures.
Nathan Bolus claimed 4-34 and Michael Hall 3-36 for South Shore, who reached their target in the 20th over.
Having impressed with the ball, Bolus then shone with the bat as he struck an undefeated 61 in taking South Shore to 84-1.
Jonathan Lee took 5-10 and Darren McKenzie 3-13 as Fylde dismissed Garstang’s thirds for 62 before they claimed victory by replying with 63-3.