Alberto Razzetti won the men's 400m medley as the hosts claimed two medals on Thursday in the opening final of the European swimming championships in Rome.
"Winning here in Rome, in this pool and in front of our public, is something incredible," said Razzetti after his victory in the historic Foro Italico pool.
"To hear the screams of the public when you hit the wall first is something I will never forget. It's really very emotional. I hope this is a good omen for the whole Italian team."
Hungarian 33-year-old Katinka Hosszu then claimed the 97th medal of her career as her team finished third, behind winners Netherlands and runners-up Great Britain, in the women's 4x200m relay final.
In the men's 800m relay, Hungary claimed gold, their third medal of the evening, anchored by Kristof Milak, the double butterfly champion at the World Championships in June. France were second and Italy third.
In the medley, the 23-year-old Razzetti made the most of the absence of world champion Leon Marchand, winning in 4 min 10.60 sec, more than six seconds outside the European record set by French swimmer Marchand in winning the world title.
Razzetti beat Hungarian David Verraszto (4:12.58) and another Italian, Pier Andrea Matteazzi (4:13.29).
"Two medals here at home is very emotional. It's a great feeling to be here, and it's an extra motivation for the whole team in the days to come," Matteazzi told AFP.
"We started well, we are really happy. We are a nice group, we are a strong team, we have seen in the last few years that Italy has done really good things. I hope and I'm sure we'll all do good things."
The evening's semifinals suggested the Italian team, the top European nation in the World Championship medal table will quickly give Razzetti and Matteazzi their wish.
World champion Nicolo Martinenghi was the fastest qualifier in the men's 100m breaststroke, comfortably quicker than Arno Kamminga of the Netherlands, the runner-up in Budapest.
In the women's 200m backstroke, two-time defending champion Margherita Panziera was more than a second-and-a-half faster than Eszter Szabo-Feltothy of Hungary.
Nyls Korstanje of the Netherlands was fastest in the 50m butterfly semis. Italian Thomas Ceccon, who won the 100m backstroke at the world championships, was third.
Britain's Ben Proud, who has had a busy schedule in a crowded summer, scratched. He won two golds, one in this event, representing England at the recent Commonwealth Games, and took the 50m freestyle gold in Budapest.
Frenchwoman Charlotte Bonnet was quickest in women's 100m free followed by Marrit Steenbergen, who then anchored the victorious Dutch relay team.
On Friday, David Popovici, the Romanian 17-year-old freestyle specialist, will make his first appearance of the championships in the 100m freestyle heats.
In Budapest, he became the first man in almost 50 years to complete the 100-200m double at the World Championships