Ian Thorpe won his personal battle with Holland's Pieter van den Hoogenband to retain his World Championships 200m freestyle title in Barcelona.
And there was glory, too, for American teenager Michael Phelps, who smashed his own 200m butterfly world record in the semi-finals.
Britain celebrated their second medal of the championships when Katy Sexton collected silver in the 100m breaststroke.
Van den Hoogenband had been quicker than Thorpe in both the heats and the semi-finals, but the Australian triumphed in the final with a time of 1min 45.14secs.
"It was an average time but I'm happy with the result," said Thorpe, who picked up his second gold of the championships and his 11th in total.
"I wanted to go out pretty fast (and) it was a relatively good swim and I'm happy."
Van den Hoogenband finished over a second behind Thorpe in 1min 46.43secs, with Australian Grant Hackett collecting the bronze to follow his silver in the 400m freestyle.
Phelps, one of Thorpe's only rivals as the world's best swimmer, destroyed his own world record in the 200m butterfly semi-finals with a time of 1min 53.93secs.
The 18-year-old is planning to swim six events in Barcelona and threatens to land a medal in each.
Phelps is targeting six gold medals in Barcelona
Like Thorpe, he holds three individual world records.
Britain's Stephen Parry finished second behind Phelps in a new British record and also qualified for the final.
And Britain's medal hopes were further boosted when James Gibson set the fastest time in qualifying for the 50m butterfly final on Wednesday.
In the 100m backstroke final, there was an upset when America's Aaron Peirsol took the title ahead of Australia's Matt Welsh.
Welsh, who won gold in the 50m butterfly in world record time on Monday, had to settle for joint silver with Russia's Arkady Vyatchanin.
Peirsol's victory made it a double celebration for his family after sister Hayley took silver in the 1500m freestyle earlier in the evening.
The event was won by Hannah Stockbauer in a European record time of 16mins 00.18secs.
Germany celebrated another gold medal when Antje Buschschulte triumphed in a thrilling 100m backstroke.
Britain's Katy Sexton put on a late charge and was catching the German with every stroke but left herself with too much to do.
Sexton shared the silver with Denmark's Louise Ornstedt.
The 100m breaststroke saw another surprise when China's Xuejuan Luo captured gold ahead of Amanda Beard of the USA and Australia's Leisel Jones.
Jones set the world record in the semi-finals but could not contend with Luo's lightning quick start.
Athough the Chinese swimmer faded badly in the final metres, Jones could not respond.