The West Lothian side travelled to the Capital having recorded 12 league wins and six RBS East Regional Shield wins so far this term.
And they eventually came through this one against their title rivals after another cracking advert for regional league rugby.
Jason Watt led the way for Livingston with two tries while John Bruton, Ross Neil and Aaron Johnston also crossed for tries and Craig Bolan kicked five points as they secured the bonus point.
The victory leaves them five points clear of Preston Lodge and 14 points ahead of RHC Cougars. RHC Cougars will have the chance to gain revenge when the two sides meet again in a fortnight in the RBS East Regional Shield final.
Elsewhere in the division on Saturday Preston Lodge won 26-24 at Linlithgow while Dunbar were edged out at Berwick 21-20 and Portobello and North Berwick both secured convincing wins over Duns and Langholm respectively.
Dalkeith kept up the pressure on RBS East Two leaders Hawick Linden with a hard fought 19-15 win at Earlston. The leaders edged out Forrester 23-20, Edinburgh Northern defeated Lismore 38-12 and Trinity Accies and Ross High lost heavily to Hawick Harlequins and Gala YM respectively.
Inverleith are seven points clear at the top of RBS East Three after they saw off Moray House 29-6 at Arboretum.