Whitehead's John Ross Galbraith made eight birdies in a six-under-par 66 on the Jubilee Course to lead the St Andrews Links Trophy by a shot.
Two years after a triple bogey eight at the 14th in the final round cost him dear and forced him to settle for third at the Home of Golf, the Whitehead man's superb opening round left him one ahead of Scotland's Jamie Stewart, Germany's Claudio Consul and Australia's David Micheluzzi.
It was a good day for many of the Irish — both the official and unofficial travellers — as Tramore's Robin Dawson shot 69, Dundalk's Caolan Rafferty a 70 and Galgorm Castle's Jordan Hood and Galway's Ronan Mullarney signed for 71s to be inside the top 30.
Defending champion Conor O'Rourke his Naas clubmate Jonathan Yates, Portmarnock's Conor Purcell and Warrenpoint's Colm Campbell are tied 35th after 72s.
Paul McBride and Jack Pierse will be disappointed with 74s while Tiarnan McLarnon (75), Rowan Lester (76), Alex Gleeson (76), Sean Flanagan (76) and Jake Whelan (80) have work to do.
St Andrews Links Trophy
66 John Ross Galbraith (Whitehead)
67 Jamie Stewart (Old Course Ranfurly Ltd), Claudio Consul (Germany), David Micheluzzi (Australia)
69 Luke Brown (New Zealand), Robin Dawson (Ireland), Charlie Strickland (Ham Manor), Alejandro Tosti (Argentina), Craig Howie (Peebles), Zach Murray (Australia)
70 Santeri Lehesmaa (Finland), Ben Hutchinson (Howley Hall), Ben Ferguson (Australia), Alejandro Del Rey González (Spain), Jack Singh Brar (Remedy Oak), Sean Towndrow (Southport & Ainsdale), Caolan Rafferty (Ireland), Matthew Jordan (Royal Liverpool), Kyle McClatchie (South Africa), Tom Harris (Castletown)
71 Vitor Londot Lopes (Portugal), Philp Geerts (Italy), Jordan Hood (Ireland), Andoni Etchenique (France), Calum Fyfe (Cawder), Jack Davidson (Llanwern), Todd Clements (Braintree), Jake Burnage (Saunton), Robert MacIntyre (Glencruitten), Liam Johnston (Dumfries & County), Connor Syme (Drumoig), Felix Mory (France), Ronan Mullarney (Ireland)
72 Conor Purcell (Ireland), Daniel Brown (Masham), Gian-Marco Petrozzi (Trentham), Bailey Gill (Lindrick), Matthew Clark (Kilmacolm), Andrew Wilson (Wynyard), Jonathan Yates (Ireland), Alfie Plant (Sundridge Park), Conor O'Rourke (Ireland), Andres Gallegos (Argentina), Lorenzo Scalise (Italy), Charlie Dann (Australia), Marco Penge (Golf at Goodwood), Jovan Rebula (South Africa), Joshua McMahon (Wallasey), Colm Campbell (Ireland), Graysen Huff (USA), Jamie Clare (Long Sutton), Matias Honkala (Finland)
73 David Boote (Walton Heath), Pavan Sagoo (Ealing), Jack Gaunt (Drayton Park), Mateusz Gradecki (Poland), Sam Done (Kenwick Park), Juuso Kahlos (Finland), Eric McIntosh (Bruntsfield Links Golfing Society Ltd), Stefano Mazzoli (Italy)
74 Dewi Merckx (Belgium), Euan Walker (Kilmarnock (Barassie)), Albert Venter (South Africa), Giulio Castagnara (Italy), Matt Saulez (South Africa), Haydn Barron (Australia), Sigot Lopez (Spain), George Burns (Williamwood), John Gough (Castle Royle Golf & Country Club), Kyle Michel (Australia), Mark Hutson (New Zealand), Paul McBride (Ireland), Blake Collyer (Australia), Min Woo Lee (Australia), Harrison Endycott (Australia), Jack Pierse (Ireland), Victor Bjorlow (Denmark)
75 Ryan Lumsden (Royal Wimbledon), Tim Harry (Vale of Glamorgan Hotel Golf & Spa Resort), Morten Toft Hansen (Denmark), William Heffernan (Australia), Tiarnan McLarnon (Ireland), Greig Marchbank (Thornhill), Tom Gandy (Rowany), Blake Windred (Australia), Darren Howie (Peebles), Sandy Scott (Nairn), Francesco Donaggio (Italy), Owen Edwards (Kendleshire (The)), Ayoub Lguirati (Morocco), William Whiteoak (Shipley), Laird Shepherd (Rye)
76 Rowan Lester (Ireland), Adrian Mata Alsdorf (Spain), Raphael Geissler (Germany), James Grierson (Australia), Alex Gleeson (Ireland), Bradley Moore (Kedleston Park), Billy McKenzie (Rowlands Castle), Giacomo Fortini (Italy), Franklin Manchest (South Africa), Christopher Maclean (Balmore Ltd), Joshua Davies (Celtic Manor Resort), Cameron Shaw (Chevin), Rafael Miranda (Ecuador), Jeff Wright (Forres), Dylan Perry (Australia), Evan Griffith (Conwy, Caernarvonshire), Andres Schonbaum (Argentina), Shae Wools-Cobb (Australia), Dylan Wu (USA), Kyle Godsman (Moray), Sean Flanagan (Ireland), Josh Hilleard (Farrington)
77 Patrick Mullins (Whitchurch (Cardiff), Dylan Naidoo (South Africa), Jamie Li (Bath), Will Porter (Carnoustie), Kyle Harman (Southerndown), Keegan De Lange (South Africa), Ryan Chisnall (New Zealand), Gregory Royston (South Africa), James Walker (Oaks (The)), Pedro Lencart (Portugal), Sami Välimäki (Finland)
78 Craig Ross (Kirkhill), Travis Smyth (Australia), Alasdair McDougall (Elderslie), Matthew Lamb (Hexham), Manuel Elvira (Spain), Rasmus Broholt Lind (Denmark), Marco H Steyn (South Africa), George Bloor (Cavendish), Ben Chamberlain (Padeswood & Buckley), Roelof Koopmans (Netherlands), Nick Poppleton (Wath)
79 Stefano Ciapparelli (Italy), Marcos Montenegro (Argentina)
80 Alex Henderson (Australia), Ilari Saulo (Finland), Edward Shannly (Linlithgow), Lucas Becht (Belgium), Jake Whelan (Ireland), Oliver Farrell (Evesham)