The opening two rounds were played over the Jubilee and Old courses, and with the cut falling at 146, 2 over par, successive rounds of 73 saw Ruben Lindsay (Turnberry) into the final day right on the cut line.
Jack Broun (Turnberry) made the cut with two shots to spare, a 74 over the Jubilee and a 70 on the Old Course giving him a level par total of 144.
Stuart Easton (Irvine) leads the Ayrshire challenge at the half way stage on one under par, his 143 total including a 68 over the Jubilee course and a 75 on the Old.
England's Charlie Thornton leads the field after 36 holes with a 137 total, seven under par.
The final two rounds, played over the Old Course, take place on Sunday the 6th of June.