Miami - Olympic superstar Michael Phelps kicked off the Orlando Pro Swim meet on Thursday with a victory in the 100m butterfly in 52.28.
Phelps, hoping to add to his stunning tally of 18 Olympic gold medals at the Rio Games in August, swam the first 50m in 24.62 and held off fellow American Tom Shields for the victory.
Shields clocked 52.35, with Brazilian Henrique Martins third in 52.59.
Germany's Aliena Schmidtke won the women's 100m fly in 59.94. Yuliya Efimova of Russia produced a season's best of 1:05.70 in winning the women's 100m breaststroke.
In the men's 100m breaststroke, Brazil's Joao Gomes edged American Josh Prenot at the wall, winning in 1:00.64 to Prenot's 1:00.66. Brazil's Felipe Lima was third in 1:00.73.
Katie Ledecky won the 200m freestyle in a time of 1:55.73 - second-fastest in the world this year behind the 1:54.43 she posted in Austin in January.
"It felt pretty good," Ledecky said. "I guess it was about where I thought I would be time-wise. I worked this morning and this afternoon on some of the details I've been working on around my turns. I was pleased with how I put it all together."
Missy Franklin, winner of four gold medals at the 2012 London Olympics, was second in 1:57.67 and Allison Schmitt was third in 1:58.18.
The women's 400m individual medley went to world championships silver medallist Maya DiRado, whose time of 4:36.82 made her the fourth-fastest this season.
Vietnam's Vien Nguyen was second in 4:39.64 ahead of American Becca Mann (4:40.44). Freestyle queen Ledecky was fourth in 4:40.95.
American Chase Kalisz won the men's 400m medley in 4:15.36, with South Africa's Sebastien Rousseau second in 4:20.06.