They beat Newbattle, conquerors of defending champions Mortonhall in the quarter-finals, 7.5-1.5 at Baberton in the first semi-final.
Turnhouse, champions for the first time two years ago, take on Musselburgh, bidding to land the prize for a first time, in the other last-four clash at Liberton this Sunday.
Making home advantage count, Turnhouse and Musselburgh beat Kingsknowe 8-1 and Craigielaw 5.5-3.5 on their respective quarter-finals.
• Bathgate’s Louis Gaughan is among the Lothians pros having to qualify for this year’s M&H Logistics Scottish PGA Championship.
Gaughan, last year’s Scottish Par-3 champion, is heading to Crieff next Wednesday for the second of two 18-hole shoot-outs for spots in the Tartan Tour’s flagship event at Gleneagles in October. Others hoping to pass the test include Craig Imlah (Craigielaw), Norman Huguet (Musselburgh) and Gordon Hillson (Winterfield).
• This year’s Babe Zaharias competition run by East Lothian Ladies County Golf Association attracted 140 competitors to Luffness New.
The main prize, the Babe Zaharias Trophy, was claimed by Kelso’s Leanne Wilson with a scratch 72, finishing four shots clear of the field.
Craigielaw’s Kay Lannin and Dianne Watson of Leven finished second and third on 76 and 77 respectively as more than £4000 was raised for Macmillan Cancer Care.
• John Fraser will be the sole Lothians player representing Scotland in the Senior Home Internationals later this year.
The Royal Burgess stalwart will be part of a seven-man side trying to claim the men’s title at Southerness for the first time since the four-cornered event was last held on Scottish soil at North Berwick in 2014.
There are no Lothians players in the ladies’ equivalent at Burnham & Berrow, where the Scots will be bidding for a first win since 2009.