The Paisley professional’s five under par effort matched the lowest round of the day of second placed Mark James as well as Sam Torrance, and saw the Scot finish fourth on eight under, four strokes behind American Tim Thelen.
McAllister looked to be falling out of the tournament as he reached the turn in level par, but a thrilling back nine of 30 saw him charge up the leaderboard and pocket £9,849 for his efforts at the Golf Club Bad Ragaz.
Torrance’s 65 saw him finish the week on five under, two shots behind eighth-placed Bill Longmuir but six ahead of Gordon Brand Jnr.
Sir Bob Charles and Gary Player continued to amaze the world of golf with their unbelievable levels of performance in Switzerland.
Charles’s first round 66 in Bad Ragaz saw the New Zealander better his age by a Senior Tour record of ten shots, while Player’s scores of 72-70-71 were a testament to the nine-time Major Champion’s fitness and competitive drive.
Charles added a 73 and a 72 to his remarkable first round to finish the week at one over par – two ahead of Player – and in a tie for 42nd place.