Dent, who finished 28th in the marathon at the 2012 London Olympics, ended Vajin Armstrong's three-year winning streak in a record 4hr 33min 37sec time last year.
That blitzed Phil Costley's 2005 record (4hr 37min 41sec) by more than four minutes and makes the Canberra runner, who also competed in three Commonwealth Games, a real chance to win back-to-back titles.
However, Christchurch's Armstrong, who finished more than 12 minutes behind Dent a year ago, cannot be taken lightly as he seeks to win the 60km trail race for the fourth time in the past five years.
Dunedin's Russell Hurring (60) might not be considered one of the favourites, but he is part of the 450-strong field in what will be his 12th time running the event.
Ruby Muir (23) will be seeking a third straight win in the women's category after comfortable wins the past two years.
She won in 5hr 42min 3sec last year and 5hr 37min 55sec in 2012. While her winning times are well off the women's record of 5hr 23min 34sec, set by Zelah Morrall in 2003, she has been the 12th overall finisher the past two years.
Muir is sure to be tested by Kapiti's Jo Johansen (34), who blitzed a world-class field in the Tarawera ultramarathon from Rotorua to Kawerau in March.
In her first serious event, she outran a field including 100km age group world record holder American Meghan Arbogast, winning the weather-shortened 70km course in 7hr 2min 43sec.
In the 27km Luxmore Grunt, Southlander Richard Ford (24) will be seeking an elusive win.
Having entered the race the past four years, he has a fourth, two thirds and second place to his name, and will be hoping it is fifth time lucky this time round.
Dunedin's Louisa Andrew will be seeking a second straight Luxmore Grunt title in the women's category after winning it in 2hr 27min 2sec a year ago.
Andrew, the women's winner of the inaugural 18km Head to the Hills run in Dunedin a fortnight ago, finished almost 5min ahead of second placed Amanda Broughton (Wellington) last year.
Hurring's daughter in-law, Kellie (31), a talented track athlete who won national titles in the 800m, 1500m, 5000m and 10,000m, could be a surprise package in the 200-strong field.
Of the 650 total entries in the 60km and 27km races, 77 have come from overseas - including Britain, Canada, the United States, Japan, Germany, Switzerland, Hong Kong, Tahiti and Australia.
-by Robert Van Royen
