No. 14-ranked Isner captured his eighth career singles title and won the title in New Zealand for the second time after his victory in 2010.
The match was similar to Isner's quarterfinal victory over fifth-seeded Philipp Kohlschreiber which went to three sets, all tiebreaks and contained no breaks of serve. Isner played six tiebreaks in 10 sets at the tournament and won five.
"This match was very tight as every match I've played this week was very tight," Isner said. "I needed every bit of it to come out on top.
"I've spent a lot of time on this court this week but as each match progressed I was getting more and more comfortable."
Isner heads into the Australian Open with a question mark hanging over his fitness because of his injured ankle.
