Scotland's Ross Cameron got the Northern Ireland EuroPro Open off to a sensational start at Galgorm Castle by hitting an opening nine-under-par 63.
Cameron's superb round of seven birdies and an eagle at his closing hole, the ninth, gives him a three-shot lead.
English trio James Busby, Chris Hanson and Graeme Clark are next best on 66 after Wednesday's play.
Bushfoot's David Jones shot a 68 with Damian Mooney one shot further back.
The day-one action included a hole-in-one from Englishman Ian Ridgway whose ace at the seventh helped him move to seven under after nine before he lost momentum on the back nine.
Derryman Jones was joined on 68 by Massereene pro David Hughes plus other Irishmen John Kelly and Noel Fox.
Former Walker Cup player Jonathan Caldwell shot a steady 70 while those on 71 include Mayobridge's Barrie Trainor and Mourne amateur Reeve Whitson.
Royal Portrush amateur Matthew McAlpin's level-par 72 included a triple bogey at the par-four 11th.
Galgorm Castle hopeful Liam Reilly, after a brilliant start which saw him moving to three under after three, finished on 73 after a double bogey at the 18th.
Scottish talent Zack Saltman was in a large group on level par, which also included Derryman Michael McGeady and Zane Scotland.
Reilly's Galgorm Castle club-mate David Kernohan, who performed impressively at last year's inaugural event, had a day to forget as he carded at 78.
But the main headline from day was Cameron's stunning course record at the newly-extended Galgorm layout.
After an opening birdie at the 10th, the Scot parred his next five holes before carding three successive birdies from the 16th.
Three more straight birdies followed from the second and after four straight pars, he ended his round in glorious fashion with an eagle at the ninth.
Cameron, who has been part of the Paul Lawrie Foundation in his native Scotland, was joint-leader after day one at the recent EuroPro event at Burhill in Surrey before slipping back to finish 31st.
Second-placed Hanson, Busby and Clark have all been in impressive form so far during the EuroPro campaign.
Clark currently leads the order of merit while Hanson and Busby occupied the first two positions in last week's event at Longhirst Hall.