The result means Biggar are now just two points below Hamilton in eighth place with the former having three matches left to play and the latter just the one.
Meanwhile, Jed are now six points behind Hamilton and in real danger of slipping in to one of the Championship divisions.
On Saturday it was all going well for the visitors in the first half and they took a 9-7 advantage into the break, their points all coming from three penalties by Iain Chisholm, with the hosts just two points back thanks to a converted try by back-row Rory Sutherland.
David McArthur then went over after the interval and the the hosts took control of proceedings with prop Bruce McNeill and centre Craig Russell (2) scoring tries while stand-off Hata Wilbore was on target with a number of kicks.
Hamilton are still in the relegation mix after losing on Friday night to promotion-chasing Glasgow Hawks.
A close first-half saw the teams go in tied at 13-13, however, after the interval, the Hawks were rampant, eventually coming out on top 67-27.
• Gala Wanderers will meet Stirling County Colts in the National Youth Cup Final on Monday, 15 April.