Biggar prevailed comfortably thanks to tries by Andy Jardine, Aird Jardine, Donald Voas, Rowan Stewart, Fraser Jackson (2), Ewan Stewart and Josh King, plus conversions by Andy Jardine (5) and Euan Bogle (3).
The Hartreemill team, who have 32 points from eight games, now only trail leaders Heriot’s Blues by four points with two games in hand.
“There’s always a banana skin waiting to trip you up these days,” Biggar secretary Mike Booth told the Carluke and Lanark Gazette.
"But it was a good solid performance against Boroughmuir. Our setpieces, lineout and scrum were working well.
"Andrew Jardine with his kicking, I believe only missed one on a very windy day, and the wind was not only high but was swirling round. So that was tremendous.
"It was a hard fought game with a lot of injuries on both sides, nothing dirty it was just hard fought.
"Although we’ve got two games in hand on Heriot’s we’ve got to win them both.”
Meanwhile, Biggar are due to hear on Thursday if their appeal to the SRU against a three-point deduction for failing to field a team in a league game at Ayr on September 25 is successful.
The postponement wasn’t Covid-related; it was due to the fact that Biggar claimed they had too many injured players to play.
Ironically, the rearranged fixture at Ayr is scheduled for this Saturday, kick-off 11am.
"I doubt we will win the appeal,” Booth said. “So we’ll have to win our next two games to make sure we are up at the top.
"We’re expecting a strong game from Ayr. It’s a very early kick-off because of the international matches that are on, so the boys will have to be up early.
"Like against Boroughmuir, it might be windy in Ayr but we seem to have a game plan for that high wind.
"We kept the ball low during the game, we kept the ball in hand so there was a good bit of game management.”
After picking up injuries last weekend, Biggar aces Jamie Orr, Sam King and Angus Thomson are all major doubts to face Ayr while there are also concerns over Andy Jardine and Fin Barr. This will have an influence on crucial matches coming up.