Costabile won the faceoff to start overtime, collected the ball and ran to the goal line, where he got off a hard shot into the upper part of the net for a quick Duke victory.
The Duke-Notre Dame contest marked the second straight year the NCAA lacrosse championship went to extra time. The 2009 title was decided when Syracuse defeated Cornell 10-9 in overtime -- the Orange's second consecutive crown.
The Blue Devils also got a pair of goals each from Zach Howell and Steve Schoeffel. Justin Turri added a marker for the winners, who finally succeeded in winning the NCAA championship after reaching the finals in both 2005 and 2007.
Zach Brenneman rippled the net three times for the Fighting Irish. Notre Dame reached the finals despite being unseeded.