Joe McMahon lifted the siege in the 52nd minute to cut Donegal's lead to four points but within a minute the game was as good as over when McFadden blasted to the net after the Tyrone defence had been ripped apart.
The goal appeared set to round off a satisfactory first half for the Irish but there was a shock in store before the break as Martinez struck in a superb half-volley to the net after the home defence appeared to switch off.