The GAA have rejected a request from The Curragh's executive to change the throw-in time of Saturday's All-Ireland Qualifier between Kildare and Tyrone.
The match is set to get underway at St Conleth's Park in Newbridge at 5pm, 20 minutes before the running of the Irish Derby at the re-developed Curragh racecourse.
There's only 5km between the venues and it is feared it may affect attendances at both fixtures.
Curragh CEO Derek McGrath says it's an 'unfortunate clash' but he 'respects' the GAA's decision.
The clash of Kildare and Tyrone will be televised live on Sky Sports as the first part of a double header before the meeting of Mayo and Armagh at 7pm in Castlebar.