The mayor received 49.4% of the vote and Kobayashi received 30.1%. University of Hawaii professor Panos Prevedouros garnered 18% of the vote.
Hannemann needed 923 additional votes to win the election outright.
"We had so little time, so little money, but it's your energy that got us here" Kobayashi told supporters gathered in Moiliili.
"Gail and I want to thank all of you who have worked very, very hard. We had eight other people who wanted this job. And now it's not one against eight, it's one on one." Mayor Hannemann said to his supporters, who were assembled at the Dole Cannery in Iwilei.
Mufi Hannemann 76,537 - 49 percent
Ann Kobayashi 46,730 - 30 percent
Panos Prevedouros 27,459 - 18 percent
J. Maly 1,449 - 1 percent
George Nitta 1,328 - 1 percent
Daniel Cunningham 701 - 0 percent
Cameron Datanagan 317 - 0 percent
Paul Manner 211 - 0 percent
Donavon Kambel 187 - 0 percent