Lauren Boyle recorded the fourth-fastest time in the world this year in winning the women's 800 metres freestyle gold at the French Open Championships overnight.
It was a hugely encouraging swim for Boyle, who will head the New Zealand swim team to compete at the Commonwealth Games in Glasgow later this month.
Four days after coming down from her training camp at altitude in Spain, Boyle clocked eight minutes 22.93 seconds in Vichy to win the 800m freestyle in a French Championship record time.
Her time was five seconds faster than her winning time at the New Zealand championships in February and four seconds off her New Zealand record.
She then jumped back in the pool just eight minutes later and finished fifth in the 200m freestyle final.
The rest of the New Zealand team also showed some promising signs following a three-week stint at their altitude training camp in Spain, while others had recently flown in from Australia.
Matthew Stanley finished third in the final of the men's 400m freestyle in 3:54.20, behind Canada's Ryan Cochrane and Australia's David McKeon - two of his likely rivals in Glasgow.
Tash Hind was sixth behind Boyle in the 200m freestyle in 2:01.00; Samantha Lee was seventh in the 100m butterfly in 1:00.54 while Laura Quilter was sixth in the 50m backstroke in 29.73.
Dylan Dunlop-Barrett clocked 3:56.25 to finish sixth in the 400m freestyle and Emma Robinson was fifth in the 800m freestyle in 8:43.69.
The NZ team will contest the second day of competition tonight before moving to their final training camp in Mallorca. The Commonwealth Games start on July 24.