Over 8,000 turned up for a real thriller which could have gone either way.
Lee Brennan was the hero for Trillick with a goal after just 13 seconds as they made a dream start.
Killyclogher led, though, 0-7 to 1-3 at the break.
The sides were level on four occasions during the second half.
Brennan then struck with the winner with a last gasp free.