Charlotte - Olympic champions Michael Phelps and Ryan Lochte remained winless heading into the final day of the Arena Pro Swim Series-Charlotte meet.
Lochte finished fourth on Saturday in the 100m backstroke, won by Serbia's Arkady Vyatchanin.
Meanwhile, Phelps - in his second meet since serving a six-month suspension - was seventh in the 200m butterfly, won by Chase Kalisz.
Lochte finished the event in 54.43 seconds - nearly three-quarters of a second behind Vyatchanin, who won in 53.69. Lochte barely missed out on medaling, coming in 0.01 seconds behind Japan's Junya Koga.
"That was my best in-season time," Lochte said. "It was a good day. I'm thinking about getting better day after day."
Phelps had a harder time in the 200m butterfly, which he had not competed in since earning the silver medal in the 2012 London Olympics. He touched in 2:00.77, more than 3 seconds behind Kalisz, who won in 1:57.58.
The duo had a potential matchup in the 100m backstroke. But Phelps withdrew from the event on Saturday morning to focus on the 200m butterfly.
Phelps and Lochte have two more potential head-to-head matchups Sunday at the Mecklenburg County Aquatic Centre - the 200m individual medley and 100m freestyle.
Other men's winners on Saturday were Josh Schneider (50m freestyle), Josh Prenot (200m breaststroke), Brazil's Cesar Cielo (50m butterfly), and Connor Jaeger (400m freestyle).
Schneider, the former world record holder in the 50m freestyle, won the event Saturday in 21.96, just 0.09 seconds ahead of Cielo.
Prenot won the 200m breaststroke in 2:09.30, finishing more than 2.3 seconds ahead of Cody Miller. Miller touched in 2:11.63.
Cielo, the gold medalist in the 50m freestyle at the 2008 Beijing Olympics, won the 50m butterfly in 23.26, beating Tim Phillips by nearly a half-second. Phillips touched in 23.71.
Jaeger won the 400m freestyle in 3:46.30, more than 1.2 seconds ahead of Conor Dwyer. Dwyer touched in 3:47.53.
Hungary's Katinka Hosszu added two more women's event wins to her total on Saturday, the 200m butterfly and 100m backstroke. Arianna Vanderpool-Wallace was also a two-time winner, in the 50m freestyle and 50m butterfly. Other winners were Micah Lawrence (200m breaststroke) and Leah Smith (400m freestyle).'
Hosszu, who won the 200m freestyle and 400m individual medley on Friday, won the 200m butterfly in 2:08.00, 0.76 seconds ahead of Cammile Adams. She added the 100m backstroke title about 15 minutes later, winning in 59.47, 0.39 seconds ahead of Kathleen Baker.
Vanderpool-Wallace won the 50m freestyle in 24.35, beating 12-time Olympic medalist Natalie Coughlin by 0.68 seconds. She then won the 50m butterfly in 25.93, 0.38 seconds ahead of Claire Donahue.
Lawrence dominated in winning the 200m breaststroke, with her time of 2:24.61 just over two seconds ahead of runner-up Martha McCabe. McCabe finished in 2:26.69.
Smith won the 400m freestyle in 4:07.45, beating Denmark's Lotte Friis by 0.84 seconds. Friis, the former world champion in the 1 500m freestyle, touched in 4:08.29.