Holywood youngster Rory McIlroy edged out leading qualifier Sean McTernan to make the semi-finals at the Irish Close Championship on Tuesday.
Rory McIlroy won the West of Ireland earlier this year
After beating Michael Brett by one hole in the third round game, McIlroy defeated McTernan in the afternoon.
Following his win over Brett, McIlroy was asked by the GUI to explain damage caused to the ninth green in the match.
Banbridge's Conor Doran beat Birr's Michael Horan 5 and 3 to set up a semi-final meeting against McIlroy.
Wins on the 11th, 12th and 13th were crucial in McIlroy's win over McTernan.
McTernan came back from four down to five to play to bring the match to the final hole, but a winning birdie ensured McIlroy's victory.
The bottom half of the draw so two equally close quarter-finals, with Aengus McAllister beating Mervyn Owens by one hole and Eddie McCormack edging out Mark Shanahan by the same margin.
In the morning, leading qualifier McTernan had beaten Banbridge's Rory Leonard by one hole while Doran beat Greg Bowden 2 and 1 to reach the last eight.
However, Clandeboye's Nicky Grant and Ballyliffin's Brendan McCarroll both bowed out at the third round stage.
Grant was beaten 3 and 2 by Portmarnock's Aengus McAllister while McCarroll lost by one hole against Mallow's Mervyn Owens.
Sean McTernan (Co. Sligo) lost to Rory McIlroy (Holywood) 2 holes
Conor Doran (Banbridge) beat Michael Horan (Birr) 5/3
Aengus McAllister (Portmarnock) beat Mervyn Owens (Mallow) 1 hole
Mark Shanahan (West Waterford) lost to Eddie McCormack (Galway) 1 hole.
Third Round results
Sean McTernan (Co. Sligo) bt Rory Leonard (Banbridge) 1 hole
Rory McIlroy (Holywood) bt Michael Brett (Portmarnock) 1 hole
Conor Doran (Banbridge) bt Greg Bowden (Hermitage) 2/1
Michael Horan (Birr) bt Pat Killeen (Claremorris) 1 hole
Aengus McAllister (Portmarnock) bt Nicky Grant (Clandeboye) 3/2
Mervyn Owens (Mallow) bt Brendan McCarroll (Ballyliffin) 1 hole
Mark Shanahan (West Waterford) bt Keith Crowley (Lee Valley) 1 hole
Eddie McCormack (Galway) bt John Waldron (Muskerry) 5/4