Great Britain's Tom Dean ended the day on the podium as he secured third place in the men's 200m freestyle at the FINA World Swimming Championships in Budapest.
The double Olympic champion - who won gold in the 200m freestyle and 4x200m freestyle in Tokyo last year - clinched GB's first swimming medal of the Championships with a time of 1:44.98.
Dean was leading the pack at the halfway mark, but 17-year-old Romanian David Popovici soon came charging forward and made history with a new world junior record of 1:43.21 to win gold.
Fellow teenager Sunwoo Hwang of South Korea took the silver, with the 19-year-old posting a time of 1:44.47 to get onto the podium after pipping Dean to top spot in the first semi-final.
However, the standout story of the day belonged to Italy's Thomas Ceccon, who broke the men's 100m backstroke world record with a phenomenal display in the pool.
Also a two-time medallist from the Tokyo 2020 games, Ceccon broke Ryan Murphy's six-year-old record of 51.85 to storm to the gold medal with 51.60.
Murphy himself was forced to settle for silver as he posted a 51.97, beating USA teammate Hunter Armstrong (51.98) to second place by a whisker.
"I have no words, there was an Olympic champion in 2016 (Murphy) and other strong people in the field, I'm pretty happy," Ceccon said during his post-race interview.
"I didn't think of any record or time before the start, I just swam my own race. For me, it's simply unbelievable."
Elsewhere, the USA's Katie Ledecky made it 17 World Championships gold medals with victory in the women's 1500m freestyle having also triumphed in the 400m event this year.
Finally, more success came Italy's way in the women's 100m breaststroke courtesy of 17-year-old Benedetta Pilato, who stormed to a memorable gold medal with 1:05.93.