Former Shamrock Rovers striker Stephen Grant fired a sensational course record 64 in the first round of the Radisson SAS sponsored West of Ireland Championship at Rosses Point.
The 29-year-old Birr native, who took up the game just six years ago, carded an eagle and five birdies in an immaculate seven-under par effort to lead by two strokes from Limerick's Patrick Sheehy.
While Sheey had six birdies and just one bogey in a superb 66, Grant put a painful back injury to the back of his mind to shave a shot off the course record set by Sweden's Rikard Karlberg just two years ago.
Baltray's Simon Ward finished a shot further back after a 67 as defending champion McIlroy began his bid for a hat-trick of title with a two under par 69 on a day of brilliant sunshine and light breezes.
Grant said: "I was bogey free and that is what I was delighted about. But it's been a nightmare with my back for three months now. I pulled my pelvis out when I played on a mini tour in Arizona earlier
this year and I have to go in for an MRI scan next week."
McIlroy was disappointed with his putting, especially on the back nine, but should have no problem making the top 64 qualifiers after finishing the day in a share of eighth place.
"I played okay on the front but terribly on the back," McIlroy said. "The greens were really bumpy and I didn't hole anything on the back nine. I was four-under after ten, had chances on 11, 12 and 13 and missed them all and then I bogeyed the 14th."
He also bogeyed the eighth and 17th but saved a brilliant par at the last with a deft lag putt over a hump, just seconds after duffing a cut up wedge from the left rough.
Radisson-SAS West of Ireland Championship, Rosses Point
Strokeplay qualifying (36 holes)
64 S Grant (Birr)
66 P Sheehy (Limerick)
67 S Ward (Co Louth)
68 A Johnston (UK), P Muray (Limerick), R Leonard (Banbridge), S
Lowry (UCD/Esker Hills)
69 N Grant (Knock), P McGrath (Dromoland), A Hogan (Newlands), R
McIlroy (Holywood), R McNamara (Headfort)
70 B Cashman (Belvoir Park), G Hall (Edenderry), D Coyle (Co Louth),
N Kearney (Royal Dublin), R Boal (Scrabo), W McCully (Donaghadee), A
71 D Downie (Sutton), T McGowan (Strandhill), B Reddan (Co Louth), C
O'Connor (UCD/Athlone), D Scully (Galway), R Kilpatrick (Banbridge),
G McDermott (Co Sligo), D Vaughan (Ardglass), D Kelleher
(Portmarnock), L Lennox
72 G O'Connor (Malahide), D McNeill (Ballybofey & Stranorlar), G
O'Flaherty (Cork), J Lyons (Birr), S Courtney (UK), D Leathern
(Lisburn), P Errity (Delgany), J Hurst (UK), R McCarthy (The Island),
K McCarthy (Kinsale), H Diamond (Holywood), S Doherty (Malone), A
73 R McGee (Spain), D Morgan (Mullingar), R Durnin (Laytown and
Bettystown), D Crowe (Dunmurry), D Lally (Tuam), M Rowe (Glasson), K
O'Neill (Strandhill), D Finn (Mallow), K Condren (Greystones), A
Wilson (Cairndhu), C Curley (Newlands), S Crowe (Dunmurry), D Lenihan
(UCD/Castle), A Condren (Greystones)
74 D Boyle (Cruit Island), M Hammond (Moyola Park), P Cutler
(Portstewart), J Toner (Woodbrook), G Carew (Edenderry), S Loftus
(Ennis), E Saxel (UK), P Higgins (Mullingar), J Waldron (Muskerry), J
McGinn (Laytown & Bettystown), A Dunbar (Rathmore), A McCormick
(Scrabo), B Galway (Cairndhu), C Cannon (UK), S Paul (Tandragee), P
Connolly (Clontarf), S Healy (Claremorris), G Boyd (Donaghadee)
75 T Walsh (Claremorris), C Doran (Banbridge), R Brannigan (Co
Louth), D Sutton (UK), D McNamara (Connemara), G Hammill (Ardglass),
D Coyne (Tuam), J McIntyre (City of Derry), P Walton (UCD/The
Island), M Crowe (Elm Park), T Bruden (UK), JP Hughes (Douglas), R
Maher (Nenagh), N Gorey (Lee Valley), C Hughes (Royal Portrush), P
Graham (Galgorm Castle), J Gannon (Seapoint), J Moore (Laytown &
Bettystown), M Poucher (Limerick), R Williams (Baltinglass), S
Miskelly (Knock), T McClements (Holywood), D McInerney (Lahinch)
76 P Killeen (Claremorris), N Lavin (Royal Dublin), M Sinclair
(Knock), E O'Sullivan (The Island), E McCormick (Galway), E Kennedy
(Strabane), M Lavelle (K Club)
77 D O'Brien (Laytown & Bettystown), D Ruddy (Thurles), D Cantrell
(Woodbrook), D Kneafsey (UK), G Nugent (Kilkenny), K Kennedy (Co
Tipperary), J Timoney (Headfort), J Mulready (Castle), M Kemmy
(Limerick), L Butler (West Waterford)
78 I Keane (Malahide), G Managh (Knock), M O'Connor (Elm Park), R
Cannon (Laytown & Bettystown), E Arthurs (Forrest Little), M McGinley
(Grange), A Meharg (Scrabo), M Horan (Birr), D Carroll (Grange), J
Turner (Royal Portrush), M Thistleton (UK) 78
79 D Hogan (Killeen), M Buggy (Castlecomer), J Patterson (Knock), A
80 G Mallon (North West), D King (Tramore), JJ Coey (Clandeboye), J
McNicholas (Ballyhaunis), D Brannigan (Seapoint)
81 A Wynne (Strandhill), T Cleary (East Clare)
82 E McAnoy (Knock), P O'Kane (Curragh)
83 B Christie (Skerries), M King (Athenry), C Martin (Kilkenny)