The pre-race favorites, Ken Glah, 36, of the United States, and Paula Newby-Fraser, 38, originally of Zimbabwe, finished third and fifth, respectively.
Glah, whose resume includes several top-10 finishes at the Hawaii Ironman, led the race through the 2.4-mile swim and the entire 112-mile bike. Chasing him throughout was Vabrousek, who was within six minutes of Glah at the bike-to-run transition.
The American faltered badly on the run, allowing Vabrousek to not only close the remaining gap, but to build a large advantage over his own. Meanwhile, Japans Tamuri Yoshinori, 31, set his sites on the lead and was able to run down Glah to pull with two minutes and 20 seconds of Vabrousek by the finish.
The Czechs winning time was 8:49:41. Yoshinori clocked in at 8:52:05 and Glah was well behind at 9:05:32. Vabrousek has already completed three Ironman triathlons this year, having won the inaugural Ironman South Africa in February and placing second in the first Ironman California in May.
In the womens race, two flat tires helped to prevent Newby-Fraser from winning her twenty-third Ironman event. Leading through much of the bike leg, Newby-Fraser was overtaken by Louise Davoren, 29, of Australia as a result of her setbacks.
A two-time, top-10 finisher at Ironman Hawaii, Davoren started the marathon in the lead, but was passed by a charging Nicole Leder, who built a five-minute lead before crossing the finish line. Leder is the wife of Ironman great Lothar Leder, also of Germany. Her winning time in her first Ironman race was 9:48:58.
Noriko Yamakura, 36, of Japan captured third place and Katja Mayer, 32, of Germany was fourth.