Fisher's attempt for a par putt on the last hole didn't fall, handing Lowry his first victory since taking an event as an amateur in 2009.
The Irishman carded a 5-under 66 Sunday -- his low round of the tournament. He came into the day three shots behind then-leader Bernd Wiesberger.
Fisher, seeking his first crown since the 2010 Irish Open, settled for sole possession of second place at minus-4 following a round of 1-under 70.
Michael Campbell (68) claimed third place at 12- under while Wiesberger stumbled into fourth at 11-under with a 73 Sunday.