Great Britain's Luke Patience and Stuart Bithell claimed silver in the men's 470 class after just falling short of gold on the south coast.
The pair came into the re-arranged medal race with second-place assured and still eyeing top spot, which they hoped to wrestle off Mathew Belcher and Malcolm Page.
Patience and Bithell needed at least one boat in between them and the Australians to take gold, but, after an impressive start, lost ground on their rivals, who finished ahead of the home favourites to claim the victory.
The medal race was originally due to take place on Thursday, but light winds on the Nothe course saw it delayed until midday on Friday. There was only six knots of wind on Friday afternoon but racing got under way as planned, with Patience and Bithell making the better start.
After chasing Belcher and Page during the pre-start, the British pair enjoyed a successful first leg and rounded the windward mark in the lead with Croatia second and their rivals in third.
However, the Australians proved why they are world champions by overtaking Patience and Bithell downwind to round the bottom mark in the lead.
Britain were behind Croatia's Sime Fantela and Igor Marenic in third, but responded well with aggressive sailing to bring the fleet back in. They rounded the third mark in fourth, though, and saw their hopes of gold fade when they had to do a penalty turn for pumping the sails in the light winds.
Patience and Bithell rounded the final mark in fourth and could only watch on as Croatia won the medal race and Belcher and Page crossed the line second to secure gold - Australia's third of the sailing regatta.
"We tried it, we got the better of them at the start and just managed to just sneak ahead," Bithell told BBC Sport. "Unfortunately we sneaked ahead of the rest of the fleet as well. We had hoped they would be there as well.
"They sailed a fantastic race, we tried to attack them when we could and hats off to them. They held their nerve and are worthy champions. We're happy with second. "