The 18-year-old Auckland swimmer Daniel Bell left his best until last at the New Zealand Open Swim Championships in Christchurch.
In the final event on the final night Bell won the 100 backstroke, edging under the qualifying mark for July's World Championships in Rome.
Bell's time also guaranteed that New Zealand has qualified a team for the men's 4 by 100 medley relay after the earlier times set by Corney Swanepoel (butterfly), Glenn Snyders (breaststroke) and Cameron Gibson (freestyle).
This is the same quartet that finished fifth in the final of medley relay at the Beijing Olympics.
It brought the New Zealand team for the world championships to nine swimmers who have qualified in 15 events.