Musselburgh opened the scoring with a try which was almost against the run of play as Biggar had started well, but which showed how dangerous ‘Burgh could be given space.
As with the 1first XV however, Biggar’s defence stood firm for large periods of the match and thwarted the home side’s best efforts.
Biggar nabbed a try of their own when a speculative kick allowed fullback Jack Warnock the chance to chase for a try.
His attempts to get to the ball drew the attention of the ‘Burgh winger who grappled Warnock to the ground off the ball, referee Law having no hesitation in awarding a penalty try.
Half time came and, just when Biggar needed another after the break, Musselburgh struck with a second and then a third score to go ahead at 17-7.
Their failure to kick conversions to these scores would ultimately prove costly.
Biggar mounted a series of attacks and, while the Burgh defence intially held firm, Biggar managed to get a score from a barn-storming run from Muir.
Bogle’s conversion brought Biggar right back into the mix at 17-14 down but a rare defensive lapse allowed ‘Burgh to score their fourth try to regain their 10 point advantage.
With barely 10 minutes remaining it was clear Biggar would have to score next and this they did through James Barr, the stand off finishing off a neat move. Bogle converted.
There were now just minutes left on the clock and, with their pack working well together, ‘Burgh tried to run the clock down with a series of clever pick and gos.
As they were deep in their own half this meant they were playing all the rugby and needed patience and real concentration.
All Biggar could do was get in low to halt the drive although ‘Burgh were not at all interested in making yards.
With only seconds to go Biggar won a penalty after an obstruction was spotted by the referee.
This could have been kicked to give Biggar a welcome draw at 24-24 but with nothing to lose and with the players clearly keen to go for the win, Biggar elected to run the ball.
Now desperate, ‘Burgh were forced into a rearguatrd action but their enthusiasm saw them concede another penalty which was kicked to the corner.
A clever short lineout ploy saw Muir cross for the crucial score.
Last week’s four pointer, which came after Kelso failed to provide opposition, had helped guarantee a place in this division next season and so Saturday’s result was not particularly crucial.
Biggar are now up to sixth place with an outside chance of catching their next opponents, Glasgow side Cartha Queens Park.