The New Zealand swimmer Lauren Boyle was edged into fifth place in the 400m freestyle on the opening night of finals at the FINA World Championships in Kazan, Russia.
The Commonwealth Games gold medallist at the distance had qualified fourth fastest with a controlled effort in 4:05.53 in the morning.
While she was more than a second faster in the final, she found herself pipped in the tight battle for the podium with one second covering third to fifth placings.
American Katie Ledecky continued in a class of her own, winning in a championship record 3:59.13 while Netherland's newcomer Sharon van Rouwendaal, a silver medallist in the 10km open water swim, surprised to win the silver medal.
Australian Jessica Ashwood set a new national record of 4:03.34 to take bronze with Commonwealth Games 800m gold medallist Jaz Carlin (GBR) fourth in 4:03.74 and Boyle fifth in 4:04.38, which is a shade outside her national record.
Boyle said she felt the swim was a solid start to her campaign in Kazan.
"I was pleased with the swim to be honest, it was just a fraction outside my best at that distance," Boyle said.
"I think it sets me up quite well for my main events to come and I am looking forward to the 1500m freestyle tomorrow."
"A medal would have been nice for sure but the swim felt good to me which is the main thing."
Earlier in the day it was a heat session of mixed fortunes, where only Boyle performed to standard.
Matt Stanley was well off the pace in the 400m freestyle, clocking 3:56.79 to be 47th fastest and some nine seconds outside his own national record, in a remarkable session where the world's number one and number three ranked swimmers, Mack Horton and David McKeon, both from Australia, missed qualifying as well.
The closest miss befell veteran Glenn Snyders, who was 9/100ths of a second outside qualifying in the men's 100m breaststroke.
The US-based swimmer went 1:00.44, but in a tightly backed field, it was the 18th fastest.
Overnight Boyle returns to the pool for heats of the 1500m freestyle, 15 year old Bobbi Gichard and US-based Corey Main begin their campaigns in the 100m backstroke while Matt Stanley has a chance to rekindle his fortunes in his favoured 200m freestyle.