North Shore swimmer Helena Gasson broke a national record to spark the first morning of action at the New Zealand Open Swimming Championships in Auckland.
Gasson clocked 2:09.84 to smash the national record in the 200m butterfly by more than a second, to be just half a second outside the qualifying time for the Rio Olympics.
The 21-year-old, formerly from the Fairfield club in the Waikato, went through the 100m mark in one minute flat on her way to a time of 2:09.84 which was more than a second under the previous record she set earlier this month at the New South Wales Opens.
Gasson will need to match or better the Fina 'A' standard of 2:09.33 in this evening's finals to earn Olympic nomination.
In other swims, Wilrich Coetzee (North Shore) was fastest in heats of the 200m butterfly in 2:00.23 with 35/100ths of a second separating the top three.
Glenn Snyders, chasing a third Olympic selection, led qualifiers in the 50m breaststroke in 27.29, only 0.2s outside his national record, with Porirua's Bronagh Ryan topping the women's heats in 32.47s.
The leading Paralympic stars, Sophie Pascoe, Mary Fisher, Nikita Howarth and Cameron Leslie, were also in action in the morning heats as they look to better the standard to be considered for selection for Rio in the evening finals.
There are 256 swimmers from 56 clubs competing at the Sir Owen G Glenn National Aquatic Centre at AUT Millennium, with heats from 10am and finals from 7pm through to Friday. Finals will be broadcast live on Sky Sport 3.