He doesn't lose his "powers." I mean, he got hit pretty hard and unexpectedly. He did not see that coming at all, so it was a surprise attack, almost like an ambush. Of course he was injured (it was enough to knock Zelda out almost completely), so when he tried to fight, he found his body still weak and still recovering from the unexpected attack.
Well in the meantimr pendio, How have you been, last time I talked to you was in that MM thread someone wrote.