Omaha - Ryan Lochte, the 2012 Olympic champion in the 400m individual medley, was denied a Rio berth on Sunday as Chase Kalisz led a changing of the guard in the punishing event at the US Olympic swimming trials.
Lochte, hindered by a groin injury suffered on the breaststroke leg in the morning heats, took the final out fast, hoping to build an insurmountable lead.
But Kalisz, 22-year-old training partner of Olympic superstar Michael Phelps, powered past the fast-fading Lochte on the breaststroke leg and held on over the finishing freestyle to win in 4:09.54.
"I had to go out faster than usual because I couldn't use my legs in breaststroke," Lochte said. "I did everything I could in that race. It just wasn't enough. (I've) just got to forget about it and move forward.
"I'm going to keep working on it day-in and day-out, and hopefully it gets better," added Lochte, an 11-time Olympic medallist who could still have a chance to qualify for a fourth Olympics in one of four more events in which he's entered.
Lochte said he considered pulling out of the final.
"But it's the Olympic trials," he said. "If I had a broken leg I'd still go out there and swim. I went out there and did my best – it wasn't enough."
Kalisz's time made him second-fastest in the world this year behind Japan's Kosuke Hagino.
Jay Litherland, who swims for the USA despite having New Zealand and Japanese citizenship as well, produced the fastest freestyle split in the field to grab second in 4:11.02 and put himself on the road to a first Olympic appearance.
Lochte was third and out of the Rio running a full second behind in 4:12.02.
Kalisz said he could barely remember the race that booked his first Olympic berth.
"Honestly the whole thing went by so fast. I feel like I'm in a different reality right now. I can't begin to explain what I'm feeling right now."
Phelps, whose 400m medley world record from 2008 still stands, has dropped the event from his programme as he pursues a fifth and final Olympic appearance.
He watched the race from the broadcast tribune and was delighted for Kalisz, but sympathized with his longtime rival Lochte.
"I know how Ryan feels," Phelps said. "That race is tough. That's one of the hardest races you can put your body through."
But Phelps thought Lochte could bounce back, despite the injury.
"Ryan is somebody who is very tough," Phelps said. "I would assume he would use this as motivation to get going.
"It'll be hard for him to do breaststroke. I don't know how it is for any other strokes, but he is somebody who is really, really tough," Phelps said.
While Phelps was revelling in his North Baltimore Aquatic clubmate Kalisz's success, he said he wasn't surprised by Litherland.
Litherland swam with Kalisz at the University of Georgia, and has spent time in altitude training with Phelps and company in Colorado.
"He's like a shark in the water," Phelps said. "He knows how to rise to the occasion."
Maya DiRado won the women's 400m medley in an impressive 4:33.73, with 2012 Olympic silver medallist Elizabeth Beisel more than three seconds behind in 4:36.81.
DiRado's time put her in the top five in the world this year.
In the only other final on the opening night of the meeting, Connor Jaeger won the men's 400m freestyle in 3:43.79, with Conor Dwyer second in 3:44.66.
Only the top two finishers in each event can book Rio berths.