Kyle Chalmers has given Australia a stunning finish to swimming's world short course championships, anchoring the 4x100m men's medley relay team to a dead-heat world record.
Australia looked like winning silver behind the United States in Sunday night's last event, but Chalmers powered home over the last 25m.
The Australian quartet of Isaac Cooper, Joshua Yong, Matthew Temple and Chalmers - and the Americans - clocked three minutes 18.98 seconds, going under the Russian Federation's 3:19.16 that had stood as the world mark since 2009.
It also meant Australia won a national record 13 golds at the Melbourne short course worlds, bettering the 12 they claimed in the 1995 and 2006 editions.
They finished second on the medal table behind the Americans' 17 golds.
Chalmers did not swim his 200m freestyle heat on Sunday morning to concentrate on the medley relay.
"These guys swam out of their skins ... that makes my job very, very easy," Chalmers said of his teammates.
"I just got the fun job of bringing it home."
It is Chalmers' third gold medal of the championships following the 100m freestyle and 4x50m freestyle relay.
Also on Sunday night, compatriot Kaylee McKeown made history with her 200m backstroke win.
She is the first woman to simultaneously hold the Olympic, Commonwealth world long course and world short course titles for the same event.
Compatriot Grant Hackett is the only other swimmer to achieve the same feat, in the 1500m.
McKeown was under her own world record pace for much of Sunday night's final but clocked 1:59.26 seconds to fall just short of the 1:58.94 she set two years ago.
American Claire Curzan pushed McKeown all the way and took silver in 2:00.53.
It is McKeown's third gold medal of the championships after she took out the 100m backstroke and was a member of the victorious 4x50m medley relay team.
She finished her championships later on Sunday night with silver in the 4x100m medley relay as the United States broke the world record.
McKeown, Jenna Strauch, Emma McKeon and Meg Harris clocked 3:44.92, but the Americans led throughout to win in 3:44.35 and better their own world mark of 3:44.52.
Canadian Maggie MacNeil opened Sunday night's session with her second world record of the event, smashing the old mark in the 100m butterfly.
MacNeil clocked 54.05 seconds to break the record by a whopping half a second.
She has won all of Canada's three gold medals at the Melbourne worlds.
American Ryan Murphy rubbed further salt into Australia's wound from two nights ago when he completed his sweep of the men's backstroke events.
He added the 200m to his 50m and 100m championships.
Murphy won the 50m title two nights ago on a re-start. Cooper was first in the initial race, but that event did not count because of a timing malfunction and Cooper eventually had to settle for silver.
South African Chad le Clos added the 100m butterfly title to his 200m win at the championships.
American Nic Fink set a championship record of 25.38 seconds when he won the 50m breaststroke and South Korean Hwang Sunwoo did the same when he took out the 200m freestyle in 1:39.72.
