OMAHA, Neb.—Michael Phelps will get another shot at Mark Spitz’s Olympic record in Beijing.

Gary Hall Jr. won’t be going to China at all.

Phelps locked up his eight-race schedule by winning the 100-meter butterfly at the U.S. swimming trials Saturday night, powering away on the return lap to easily beat world-record holder Ian Crocker. The winning time was 50.89 seconds, about a half-second slower than Crocker’s 3-year-old mark of 50.40.

“This week turned out how I wanted it to,” Phelps said. “I’m ready for the challenge that lies ahead of me. At the Olympics, it’s going to be harder than it was here. It’s a higher level. And you add the relays in there, and it’s the Olympic Games. Hopefully, it’s something I can be successful at.”

Although Phelps had to be content with setting two world records in Omaha, Margaret Hoelzer put her name in the book with a stunning win in the 200 backstroke.

The 25-year-old got a great surge off the wall heading into her third lap, then closed strong to finish in 2:06.09, beating the record of 2:06.39 set by Zimbabwe’s Kirsty Coventry in February. It was the ninth world record of the meet.

Fifteen-year-old Elizabeth Beisel, a rising star in American swimming, rallied to take the second Olympic spot in 2:06.92. Hard-luck Hayley McGregory finished third again, matching her finish in the 100 back and costing her a berth on the Beijing team.

Hall, too, was denied and won’t get a chance to go for his third straight Olympic gold in the 50 freestyle. The 33-year-old iconoclast came on deck wearing a red, white and blue cape and used his hands as six-shooters, hoping to take down his younger rivals in his only event of the trials.

But Garrett Weber-Gale touched first with an American record of 21.47, while defending world champion Ben Wildman-Tobriner took the second Olympic spot in 21.65.