Jowsey (18) has made a steady rise through the ranks in the three years he has contested the event. He was third in his first attempt in 2009, second a year later and the champion last year.
He is a 400m-800m specialist on the track and finished fourth in the 800m at the New Zealand secondary schools track and field championships in December.
His strongest opposition will come from Robert Jopp (Hill City), who won a bronze medal in the senior boys 200m at the national secondary schools championships.
The challengers will be Blair Grant (Taieri) and Bevan Stevens (Caversham).
Stevens could be the dark horse because he has sharpened his sprint speed since joining Mike Weddell's training squad.
He also has the endurance gained from running the training miles over the past 10 years.
The start is important and the runner who gets the jump when the first of the 10 chimes ring out from the Town Hall clock has the advantage.
The runner who reaches the top first can control the race on the downhill stretch to the Regent Theatre. If Stevens is in front at that point, he should win the race.
Sophie Napper (Ariki), a key member of the Columba College team that won a gold medal in the senior girls 4 x 100m relay at the national schools championships, is the clear favourite in the women's race.
She was named in the New Zealand secondary schools team after the championships in Wellington last month.
None of the runners in the fields looks likely to break the race records or beat the 10 chimes of the Town Hall clockThe men's record was run by Cory Innes (Taieri) in 2008.
His time was 31.63sec. Anna Smythe (Hill City) broke the women's record with her time of 35.10sec in 1998.
The Time Buster starts and finishes outside the New Zealand Shop, the sponsor of the event.
The prizes available are $300 for the first male and female to cross the finish line.
There is a bonus payment of $500 for breaking the men's or women's records and an additional $250 for finishing before the 10th chime.
Time Buster
At a glance
Venue: Octagon.
• First held: 1992.
• Distance: 243m.
• Field: Six men, six women.
• Records: Cory Innes (men) 31.63sec (2008), Anna Smythe (women) 35.01sec (1998).
• The field: Men - Robert Jopp, Ben Jowsey, Blair Grant, Will Sew Hoy, Chan Butson, Bevan Stevens; women - Sophie Napper, Jasmine Ng, Zoey Flockton, Natalie Hill, Danielle Geldeman, Rosie Duffy.
