The Swans had stormed into finals contention after winning three of their past four matches, but went down to the Hawks in round 14.
Mt Lawley posted a mammoth target of 7-413 on the first day, with the Swans bowled out for 154 inside 46 overs in reply.
Julian Crudeli (34no) and Tim Armstrong (27) were the only batsmen to show any fight.
Midland-Guildford’s big guns Dominic Sibley (21) and Stewart Walters (3) lost their wickets early in the piece.
The Swans will play for pride this Saturday against Bayswater-Morley at Lilac Hill.