OMAHA, Neb. » Back and forth they went, Michael Phelps and Ryan Lochte turning the U.S. Olympic trials into nothing more than a match race between the world’s two greatest swimmers.

They might as well have been the only guys in the pool, their arms whirling furiously, the two of them never more than a few inches apart. Then, at the wall, they thrust out their right arms.

Phelps touched first.

By five-hundredths of a second.

Sending an emphatic message to his biggest rival, Phelps stretched out to win a thrilling 200-meter freestyle Wednesday night, setting up a duel in London that just gets more tantalizing with every race.

"Neither one of us likes to lose," Phelps said. "We’re going to have a lot of races like that over the next couple of weeks. That’s how it always seems to shake out when we’re in the water."

Can’t wait until the next one.

Lochte won the 400 individual medley on the opening night of the trials, his third straight major victory over the winningest Olympian ever. But Phelps isn’t going down that easily.

He got off to a stronger start than usual, leading at the first turn and holding the advantage through all four laps. Both swimmers went stroke for stroke down the stretch. But Phelps stretched out his right arm at the wall, touching just ahead of Lochte. The winning time was 1 minute, 45.70 seconds.

"I’m glad I got one back," Phelps said. "But we’re going to have a lot more of those"

Phelps’ victory was even more impressive, given his busy night. He

didn’t even have time to celebrate, hustling back to the warm-down pool to get ready for the semifinals of the 200 butterfly. He came back 40 minutes later to post the third-fastest qualifying time, moving on to today’s final looking to lock up a chance to defend the gold he won at the last two Olympics.

"I feel old," the 26-year-old Phelps quipped.

Speaking of busy, Missy Franklin left no doubt that she is swimming’s next big star with a stunning performance in the 100 backstroke, signaling a changing of the guard in an event Natalie Coughlin captured at the last two Olympics.

Coming back to the pool just 20 minutes after qualifying for the final of the 200 freestyle, the 17-year-old "Missile" chased down Coughlin on the return lap to win with an American record of 58.85.

"I have dreamed of this moment, but I never thought it would come true at 17 years old," Franklin said. "Dreams do come true."

Coughlin got off to a typically strong start and was under world-record pace at the turn. But the 29-year-old couldn’t hold off two teenagers. Eighteen-year-old Rachel Bootsma got past the 11-time Olympic medalist, as well, claiming the second Olympic spot in 59.49.

Coughlin was third in 1:00.06 and has only one more chance to make her third Olympic team: the 100 freestyle. She swam over to congratulate Franklin in the middle of the pool, but her chances of making a third straight Olympic team are hanging in the balance.

She hopes to have a shot at winning at least one medal in London, which would pull her even with Jenny Thompson and Dara Torres as the most decorated U.S. female Olympians.

"I did exactly what I needed to do tonight and gave it my best. That’s really all you can ask for," Coughlin said. "I have won two golds in that. I am very proud of what I’ve done in the 100 backstroke and it’s time for Missy and Bootsma."

In another final, Breeja Larson pulled off a huge upset in the 100 breaststroke, beating Rebecca Soni and world-record holder Jessica Hardy. Larson won in 1:05.92, while Soni rallied to get the second spot on the team at 1:05.99.

"Maybe after tonight my dad owes me a steak dinner," said Larson, who is competing in her first trials. "After the steak has settled in, I might believe it."

Hardy finished third — about a half-second too slow to earn a spot in London. She was eager for redemption after missing out on the 2008 Olympics because of a failed doping test, which resulted in a one-year suspension. An arbitration panel reduced the normal two-year ban, ruling that Hardy was the victim of a tainted supplement.

Also, Matt Grevers captured the men’s 100 backstroke with the second-fastest time ever, 52.08. Nick Thoman finished second in 52.86 to take the second spot on the Olympic team.

Phelps’ winning time was nearly 3 seconds slower than his gold-medal effort in Beijing, though that was aided by high-tech bodysuits, which have since been banned by the world governing body.

"We didn’t really try to pick it up until, like, the last 75, so I’ll save that for the Olympics," said Lochte, whose time was 1:45.75. "I was just really relaxed for the first 125, and then the last 75, I was like, ‘All right, now we’ve got to put it in gear.’ So I kind of waited a little late, but I’ll take it."

They’ll have one more showdown in Omaha, facing off in the 200 individual medley. Then it’s off to the meet that really matters, where Phelps is plotting another eight-event program in what he says will be his final Olympics, giving him a chance to match his record performance four years ago.

Lochte is standing in the way this time.

"I love racing against him," the Floridian said. "It was really fun."