Siblings Michael and Jean Beaumont set the standard at the Great Naseby Water Race on Saturday, both smashing records in the 100km event.
Porirua runner Jean (44) won the women's 100km distance in a time of 9hr 56min, breaking last year's record time of 11hr 53min, set by Lisa Nicholl, of Rangiora.
Her younger brother Michael (33), of the Kapiti Coast, took top honours in the men's 100km distance, finishing in 9hr 15min and slicing 22 minutes off the record time.
"It was a top effort by both of them, who put their heart and soul into it," race organiser Jamie Sinclair, of Dunedin, said.
The Naseby race, which is the only ultra marathon event in Otago, attracted a field of 37 runners from all over the country.
The course is comprised of a 10km circuit through the Naseby forest, following the water race for part of the way.
Competitors have the choice of a 50km, 80km or 100km individual run or a 60km team event.
"Because the event takes so long, the 100km competitors start at 6am so they run that first 10km lap in the dark, wearing headlamps," Sinclair said.
Twelve runners entered the 50km event and the first woman home was Aimee Manning (nee Connor), of Dunedin, who completed the course in 5hr 22min, breaking her own record set two years ago.
Vivian Cheng (Wellington) was second just a minute behind, on 5hr 23min and Lynn Bosworth (Dunedin) was third on 5hr 37min.
Dunedin runner Brian Pascoe also broke a record in the men's 50km, taking 6min off the record, to win the event in 3hr 49min.
Rudi Keggenhoff (Geraldine) was second in 4hr 26min and Jamie Sinclair was third in 5hr 8min.
There was only one competitor in the 80km distance - Barry Kiwara (Hamilton), who finished in 10hr 40min.
Kiwara has competed in more than 100 marathons, Sinclair said.
Dunedin runners fared well in the teams event.
The winning team was Andrew Perry and Ron McClay-Barnes, who finished the 60km in 4hr 42min, while Grant Koedyk and Gerald Scoones (Dunedin) were second in 5hr 31min.
Team members each complete three laps of the course.
The first women's team was Lesley Stevens and Christine Frost (Dunedin) in 6hr 54min, followed by Kyra Jones and Lesley Taylor (Dunedin) in 7hr 10min.
Dunedin runner Matt Bixley was second in the 100km event (9hr 38min) and Glen Sutton (Dunedin) was third (9hr 45min).
