Experienced Kiwis Jo Lawn and Sam Warriner will take on defending champion Annabel Luxford in the Asia Pacific Championship at Ironman 70.3 Auckland this month.
Lawn, a seven-times Ironman New Zealand winner, is shifting her focus to half ironman while former Olympic distance world No.1 Warriner is continuing to develop her expertise in the longer multisport discipline.
Both will have to find top form if they want to better Australia's Luxford, who finished third at the half ironman world championships in Nevada last year.
Scotland's Catriona Morrison, a four-time duathlon world champion, is also a confirmed starter as she looks to work her way back into form after double Achilles tendon surgery and a broken collar bone.
Lawn, who turned 40 last week, says she's opted to put the full ironman distance to one side in favour of the 70.3 events this year.
"With 70.3, you can race two or three in a row. If something goes wrong, you can just say okay and race one next week or the week after."
Warriner, 42, enjoyed an outstanding career at the Olympic distance including the Athens and Beijing Olympics, a world championship medal, seven World Cup wins and the overall World Cup crown in 2008.
Her move to the longer distance has included victory at Ironman New Zealand in 2011.
She had time out for the birth of daughter Lola in 2012 and mixed motherhood with success in winning Ironman 70.3 Cairns in 2013.
Warriner, battling a hamstring injury, is using the race to kickstart her 2014 season, where she plans to compete in full Ironman and 70.3 races around Asia Pacific.