Ryan Lochte set the pace in the men's 200m freestyle Monday as the United States looked to recover strongly from their stinging world championships defeat in the 4x100m relay.
Lochte steamed home in 1min 46.34sec to lead the heats ahead of Dutchman Sebastiaan Verschuren, defending champion Paul Biedermann, in-form South Korean Park Tae-Hwan and US superstar Michael Phelps.
"I didn't expect it to hurt that much," said the three-time Olympic gold medallist, ahead of the semi-finals later on Monday.
"It was pretty good swim for a morning swim for me. Tonight I think I'll have Michael next to me so it's definitely going to be a good race."
America's Natalie Coughlin was quickest in the women's 100m backstroke and team-mate Rebecca Soni led the 100m breaststroke timings ahead of Ji Liping of China.
France's European champion Camille Lacourt topped the men's 100m backstroke standings with Britain's world 50m title-holder Liam Tancock fourth. Denmark's Lotte Friis was fastest in the women's 1500m heats.
In Monday's evening finals, Jessica Schipper carries Australian hopes in the women's 100m butterfly, a day after her team-mates buried the United States' seven-year world and Olympic 4x100m freestyle men's relay streak.
Controversial Brazilian Cesar Cielo is favourite in the men's 50m butterfly, just days after he was cleared to compete despite testing positive for a banned substance.
And four-time Olympic gold medallist Kosuke Kitajima of Japan will bid to win his first world 100m breaststroke title in eight years.
Source: AFP American Edition
