OMAHA, Neb. – On a night at the Olympic Trials when the old guard of American swimming was fully under siege, Zach Harting applied the final flourish of insouciance.

The 18-year-old Louisville sophomore came strutting out for his semifinal heat of the 200-meter butterfly wearing a Batman mask. Keep in mind, the kid was about ready to race Michael Phelps His Ownself, in front of 14,132 fans. And here he was pointing into the CenturyLink Center stands, egging on the crowd, turning this pressurized moment into a Halloween gag.

"I just thought, 'I'm going to do what Batman does – I'm going to kick some butt,' " said Harting, who is, shall we say, a quirky young man. "It kind of loosened me up. I'm sure [Phelps] thought, 'What's that kid doing?' "

That's probably what a lot of longtime stars of the sport thought while they were being swept aside in something of a hostile takeover of the American Olympic lineup. Four finals were contested Tuesday night, and all four were won by first-time Olympians.

Of course, Phelps dispatched Batman with ease, advancing in the 200 fly in dominant fashion. But plucky young Harting finished sixth and is going with Phelps into that eight-man final, along with six other guys who have never made an Olympic team.

View photos Olivia Smoliga celebrates after winning the women's 100-meter backstroke. (AP) More

That has been the story of the Olympic Trials to date. Some of the most familiar faces in swimming – household names every four years – are being left behind.

Defending women's 100 backstroke Olympic gold medalist Missy Franklin finished a badly beaten seventh in that event. Natalie Coughlin, who has won 12 Olympic medals, was eighth and last in the final. Stepping up were 21-year-old Olivia Smoliga and 19-year-old Kathleen Baker to take their place.

After the finish, Franklin hung onto the wall for a couple of seconds and dropped her head. It took her a moment before she could transition into her trademark smile. Coughlin was composed in defeat but the reality is that, at 33, she's on the verge of Olympic obsolescence.

"That's just the natural progression," Coughlin said of watching the younger swimmers blow past.

Defending men's 100 backstroke Olympic gold medalist Matt Grevers finished third, beaten by 20-year-old Ryan Murphy and 30-year-old Olympic rookie David Plummer. Grevers was half a second out of second place, a pretty wide margin. The six-time Olympic medalist handled it with customary class, but it wasn't an easy moment.

"I think I'm a little stunned," Grevers said. "When I let it set in, I'm going to be more distraught."

In the men's 200 freestyle, 19-year-old Texas sophomore Townley Haas snuck his hand on the wall .01 ahead of Olympic vet Conor Dwyer. Eleven-time Olympic medalist Ryan Lochte, battling through a groin pull, labored home fourth to secure a relay spot – but after being shut out in the 400 IM, his chances of being a marquee Olympian yet again are dwindling.

"I'm proud I made the team," Lochte said. "… The U.S. is the hardest country to make the team."

And in the women's 100 breaststroke, past Olympians Jessica Hardy and Breeja Larson were left far behind by newcomers Lilly King, a 19-year-old Indiana sophomore, and Katie Meili, a 25-year-old who took the less-traveled road through the Ivy League (Columbia) to the Olympics.

"It's super exciting, the changing of the guard," King said. "It's sad to see those great swimmers go, but there are a lot of newcomers stepping up."

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