USA swimmer Michael Phelps struggled to find form at the Arena Pro Swim Series meet in North Carolina as he finished seventh in the 200m butterfly.
The 29-year-old, who returned to the sport last year after initially retiring at the end of the London 2012 Olympics, was competing in the event for the first time in three years.
Phelps, who is targeting a spot at the Rio 2016 Games, clocked a time of 2:00.77 in the race, three seconds behind winner Chase Kalisz.
The American, who recently served a six-month suspension following a drink-driving conviction, is the most decorated Olympian of all time with 22 medals.
