Castle's Alex Gleeson produced a sensational back nine birdie barrage to card an opening seven under 65 in the Liberty Gauteng North Open in South Africa.
The Irish international made eight birdies in a stunning round with seven of them coming in his last 12 holes at Irene Country Club, where he covered the back nine in 31 thanks to four birdies in his last five holes.
The Dubliner is tied for second spot with Clifford Thompson, two strokes behind Louis Albertese, who posted an immaculate, nine under par 63 on day one.
Hermitage's Rowan Lester is the next best of the Irish in 21st place after a 70 while Robin Dawson, Stuart Grehan, Jack Hume, Dermot McElroy and John-Ross Galbraith are tied 46th after level par 72s.
Warrenpoint's Colm Campbell Jnr had two bogeys and a birdie in a 73 to lie 64th.